Class: String

Inherits:
Object show all
Includes:
Comparable, Enumerable
Defined in:
string.c

Overview

A String object holds and manipulates an arbitrary sequence of bytes, typically representing characters. String objects may be created using String::new or as literals.

Because of aliasing issues, users of strings should be aware of the methods that modify the contents of a String object. Typically, methods with names ending in “!” modify their receiver, while those without a “!” return a new String. However, there are exceptions, such as String#[]=.

Instance Method Summary collapse

Methods included from Comparable

#<, #<=, #>, #>=, #between?

Methods included from Enumerable

#all?, #any?, #collect, #cycle, #detect, #drop, #drop_while, #each_cons, #each_slice, #each_with_index, #entries, #enum_cons, #enum_slice, #enum_with_index, #find, #find_all, #find_index, #first, #grep, #group_by, #inject, #map, #max, #max_by, #member?, #min, #min_by, #minmax, #minmax_by, #none?, #one?, #reduce, #reject, #reverse_each, #select, #sort, #sort_by, #take, #take_while, #to_a, #zip

Constructor Details

#new(str = "") ⇒ String

Returns a new string object containing a copy of str.



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# File 'string.c', line 335

static VALUE
rb_str_init(argc, argv, str)
int argc;

Instance Method Details

#%(arg) ⇒ String

Format—Uses str as a format specification, and returns the result of applying it to arg. If the format specification contains more than one substitution, then arg must be an Array containing the values to be substituted. See Kernel::sprintf for details of the format string.

"%05d" % 123                       #=> "00123"
"%-5s: %08x" % [ "ID", self.id ]   #=> "ID   : 200e14d6"

Returns:



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# File 'string.c', line 461

static VALUE
rb_str_format(str, arg)
VALUE str, arg;

#*(integer) ⇒ String

Copy—Returns a new String containing integer copies of the receiver.

"Ho! " * 3   #=> "Ho! Ho! Ho! "

Returns:



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# File 'string.c', line 419

VALUE
rb_str_times(str, times)
VALUE str;

#+(other_str) ⇒ String

Concatenation—Returns a new String containing other_str concatenated to str.

"Hello from " + self.to_s   #=> "Hello from main"

Returns:



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# File 'string.c', line 391

VALUE
rb_str_plus(str1, str2)
VALUE str1, str2;

#<<(fixnum) ⇒ String #concat(fixnum) ⇒ String #<<(obj) ⇒ String #concat(obj) ⇒ String

Append—Concatenates the given object to str. If the object is a Fixnum between 0 and 255, it is converted to a character before concatenation.

a = "hello "
a << "world"   #=> "hello world"
a.concat(33)   #=> "hello world!"

Overloads:



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# File 'string.c', line 853

VALUE
rb_str_concat(str1, str2)
VALUE str1, str2;

#<=>(other_str) ⇒ -1, ...

Comparison—Returns -1 if other_str is less than, 0 if other_str is equal to, and +1 if other_str is greater than str. If the strings are of different lengths, and the strings are equal when compared up to the shortest length, then the longer string is considered greater than the shorter one. If the variable $= is false, the comparison is based on comparing the binary values of each character in the string. In older versions of Ruby, setting $= allowed case-insensitive comparisons; this is now deprecated in favor of using String#casecmp.

<=> is the basis for the methods <, <=, >, >=, and between?, included from module Comparable. The method String#== does not use Comparable#==.

"abcdef" <=> "abcde"     #=> 1
"abcdef" <=> "abcdef"    #=> 0
"abcdef" <=> "abcdefg"   #=> -1
"abcdef" <=> "ABCDEF"    #=> 1

Returns:

  • (-1, 0, +1) 


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# File 'string.c', line 1016

static VALUE
rb_str_cmp_m(str1, str2)
VALUE str1, str2;

#==(obj) ⇒ Boolean

Equality—If obj is not a String, returns false. Otherwise, returns true if str <=> obj returns zero.

Returns:

  • (Boolean) 


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# File 'string.c', line 950

static VALUE
rb_str_equal(str1, str2)
VALUE str1, str2;

#=~(obj) ⇒ Fixnum?

Match—If obj is a Regexp, use it as a pattern to match against str,and returns the position the match starts, or nil if there is no match. Otherwise, invokes obj.=~, passing str as an argument. The default =~ in Object returns false.

"cat o' 9 tails" =~ /\d/   #=> 7
"cat o' 9 tails" =~ 9      #=> false

Returns:



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# File 'string.c', line 1313

static VALUE
rb_str_match(x, y)
VALUE x, y;

#[](fixnum) ⇒ Fixnum? #[](fixnum, fixnum) ⇒ String? #[](range) ⇒ String? #[](regexp) ⇒ String? #[](regexp, fixnum) ⇒ String? #[](other_str) ⇒ String? #slice(fixnum) ⇒ Fixnum? #slice(fixnum, fixnum) ⇒ String? #slice(range) ⇒ String? #slice(regexp) ⇒ String? #slice(regexp, fixnum) ⇒ String? #slice(other_str) ⇒ String?

Element Reference—If passed a single Fixnum, returns the code of the character at that position. If passed two Fixnum objects, returns a substring starting at the offset given by the first, and a length given by the second. If given a range, a substring containing characters at offsets given by the range is returned. In all three cases, if an offset is negative, it is counted from the end of str. Returns nil if the initial offset falls outside the string, the length is negative, or the beginning of the range is greater than the end.

If a Regexp is supplied, the matching portion of str is returned. If a numeric parameter follows the regular expression, that component of the MatchData is returned instead. If a String is given, that string is returned if it occurs in str. In both cases, nil is returned if there is no match.

a = "hello there"
a[1]                   #=> 101
a[1,3]                 #=> "ell"
a[1..3]                #=> "ell"
a[-3,2]                #=> "er"
a[-4..-2]              #=> "her"
a[12..-1]              #=> nil
a[-2..-4]              #=> ""
a[/[aeiou](.)\1/]      #=> "ell"
a[/[aeiou](.)\1/, 0]   #=> "ell"
a[/[aeiou](.)\1/, 1]   #=> "l"
a[/[aeiou](.)\1/, 2]   #=> nil
a["lo"]                #=> "lo"
a["bye"]               #=> nil

Overloads:



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# File 'string.c', line 1638

static VALUE
rb_str_aref_m(argc, argv, str)
int argc;

#[]=(fixnum) ⇒ Object #[]=(fixnum) ⇒ Object #[]=(fixnum, fixnum) ⇒ Object #[]=(range) ⇒ Object #[]=(regexp) ⇒ Object #[]=(regexp, fixnum) ⇒ Object #[]=(other_str) ⇒ Object

Element Assignment—Replaces some or all of the content of str. The portion of the string affected is determined using the same criteria as String#[]. If the replacement string is not the same length as the text it is replacing, the string will be adjusted accordingly. If the regular expression or string is used as the index doesn’t match a position in the string, IndexError is raised. If the regular expression form is used, the optional second Fixnum allows you to specify which portion of the match to replace (effectively using the MatchData indexing rules. The forms that take a Fixnum will raise an IndexError if the value is out of range; the Range form will raise a RangeError, and the Regexp and String forms will silently ignore the assignment.



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# File 'string.c', line 1830

static VALUE
rb_str_aset_m(argc, argv, str)
int argc;

#each_byte {|fixnum| ... } ⇒ String

Passes each byte in str to the given block.

"hello".each_byte {|c| print c, ' ' }

produces:

104 101 108 108 111

Yields:

  • (fixnum)

Returns:



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# File 'string.c', line 3816

static VALUE
rb_str_each_byte(str)
VALUE str;

#length ⇒ Integer

Returns the length of str.

Returns:



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# File 'string.c', line 355

static VALUE
rb_str_length(str)
VALUE str;

#capitalize ⇒ String

Returns a copy of str with the first character converted to uppercase and the remainder to lowercase.

"hello".capitalize    #=> "Hello"
"HELLO".capitalize    #=> "Hello"
"123ABC".capitalize   #=> "123abc"

Returns:



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# File 'string.c', line 2952

static VALUE
rb_str_capitalize(str)
VALUE str;

#capitalize! ⇒ String?

Modifies str by converting the first character to uppercase and the remainder to lowercase. Returns nil if no changes are made.

a = "hello"
a.capitalize!   #=> "Hello"
a               #=> "Hello"
a.capitalize!   #=> nil

Returns:



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# File 'string.c', line 2912

static VALUE
rb_str_capitalize_bang(str)
VALUE str;

#casecmp(other_str) ⇒ -1, ...

Case-insensitive version of String#<=>.

"abcdef".casecmp("abcde")     #=> 1
"aBcDeF".casecmp("abcdef")    #=> 0
"abcdef".casecmp("abcdefg")   #=> -1
"abcdef".casecmp("ABCDEF")    #=> 0

Returns:

  • (-1, 0, +1) 


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# File 'string.c', line 1057

static VALUE
rb_str_casecmp(str1, str2)
VALUE str1, str2;

#center(integer, padstr) ⇒ String

If integer is greater than the length of str, returns a new String of length integer with str centered and padded with padstr; otherwise, returns str.

"hello".center(4)         #=> "hello"
"hello".center(20)        #=> "       hello        "
"hello".center(20, '123') #=> "1231231hello12312312"

Returns:



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# File 'string.c', line 4731

static VALUE
rb_str_center(argc, argv, str)
int argc;

#each_char {|cstr| ... } ⇒ String

Passes each character in str to the given block.

"hello".each_char {|c| print c, ' ' }

produces:

h e l l o

Yields:

  • (cstr)

Returns:



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# File 'string.c', line 3856

static VALUE
rb_str_each_char(VALUE str)
{
    int i, len, n;
    const char *ptr;

    RETURN_ENUMERATOR(str, 0, 0);
    str = rb_str_new4(str);
    ptr = RSTRING(str)->ptr;
    len = RSTRING(str)->len;
    for (i = 0; i < len; i += n) {
        n = mbclen(ptr[i]);
        rb_yield(rb_str_substr(str, i, n));
    }
    return str;
}

#chomp(separator = $/) ⇒ String

Returns a new String with the given record separator removed from the end of str (if present). If $/ has not been changed from the default Ruby record separator, then chomp also removes carriage return characters (that is it will remove \n, \r, and \r\n).

"hello".chomp            #=> "hello"
"hello\n".chomp          #=> "hello"
"hello\r\n".chomp        #=> "hello"
"hello\n\r".chomp        #=> "hello\n"
"hello\r".chomp          #=> "hello"
"hello \n there".chomp   #=> "hello \n there"
"hello".chomp("llo")     #=> "he"

Returns:



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# File 'string.c', line 4086

static VALUE
rb_str_chomp(argc, argv, str)
int argc;

#chomp!(separator = $/) ⇒ String?

Modifies str in place as described for String#chomp, returning str, or nil if no modifications were made.

Returns:



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# File 'string.c', line 3994

static VALUE
rb_str_chomp_bang(argc, argv, str)
int argc;

#chop ⇒ String

Returns a new String with the last character removed. If the string ends with \r\n, both characters are removed. Applying chop to an empty string returns an empty string. String#chomp is often a safer alternative, as it leaves the string unchanged if it doesn’t end in a record separator.

"string\r\n".chop   #=> "string"
"string\n\r".chop   #=> "string\n"
"string\n".chop     #=> "string"
"string".chop       #=> "strin"
"x".chop.chop       #=> ""

Returns:



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# File 'string.c', line 3920

static VALUE
rb_str_chop(str)
VALUE str;

#chop! ⇒ String?

Processes str as for String#chop, returning str, or nil if str is the empty string. See also String#chomp!.

Returns:



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# File 'string.c', line 3883

static VALUE
rb_str_chop_bang(str)
VALUE str;

#<<(fixnum) ⇒ String #concat(fixnum) ⇒ String #<<(obj) ⇒ String #concat(obj) ⇒ String

Append—Concatenates the given object to str. If the object is a Fixnum between 0 and 255, it is converted to a character before concatenation.

a = "hello "
a << "world"   #=> "hello world"
a.concat(33)   #=> "hello world!"

Overloads:



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# File 'string.c', line 853

VALUE
rb_str_concat(str1, str2)
VALUE str1, str2;

#count([other_str]) ⇒ Fixnum

Each other_str parameter defines a set of characters to count. The intersection of these sets defines the characters to count in str. Any other_str that starts with a caret (^) is negated. The sequence c1–c2 means all characters between c1 and c2.

a = "hello world"
a.count "lo"            #=> 5
a.count "lo", "o"       #=> 2
a.count "hello", "^l"   #=> 4
a.count "ej-m"          #=> 4

Returns:



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# File 'string.c', line 3451

static VALUE
rb_str_count(argc, argv, str)
int argc;

#crypt(other_str) ⇒ String

Applies a one-way cryptographic hash to str by invoking the standard library function crypt. The argument is the salt string, which should be two characters long, each character drawn from [a-zA-Z0-9./].

Returns:



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# File 'string.c', line 4478

static VALUE
rb_str_crypt(str, salt)
VALUE str, salt;

#delete([other_str]) ⇒ String

Returns a copy of str with all characters in the intersection of its arguments deleted. Uses the same rules for building the set of characters as String#count.

"hello".delete "l","lo"        #=> "heo"
"hello".delete "lo"            #=> "he"
"hello".delete "aeiou", "^e"   #=> "hell"
"hello".delete "ej-m"          #=> "ho"

Returns:



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# File 'string.c', line 3300

static VALUE
rb_str_delete(argc, argv, str)
int argc;

#delete!([other_str]) ⇒ String?

Performs a delete operation in place, returning str, or nil if str was not modified.

Returns:



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# File 'string.c', line 3244

static VALUE
rb_str_delete_bang(argc, argv, str)
int argc;

#downcase ⇒ String

Returns a copy of str with all uppercase letters replaced with their lowercase counterparts. The operation is locale insensitive—only characters “A” to “Z” are affected.

"hEllO".downcase   #=> "hello"

Returns:



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# File 'string.c', line 2889

static VALUE
rb_str_downcase(str)
VALUE str;

#downcase! ⇒ String?

Downcases the contents of str, returning nil if no changes were made.

Returns:



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# File 'string.c', line 2853

static VALUE
rb_str_downcase_bang(str)
VALUE str;

#dump ⇒ String

Produces a version of str with all nonprinting characters replaced by \nnn notation and all special characters escaped.

Returns:



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# File 'string.c', line 2691

VALUE
rb_str_dump(str)
VALUE str;

#each(separator = $/) {|substr| ... } ⇒ String #each_line(separator = $/) {|substr| ... } ⇒ String

Splits str using the supplied parameter as the record separator ($/ by default), passing each substring in turn to the supplied block. If a zero-length record separator is supplied, the string is split into paragraphs delimited by multiple successive newlines.

print "Example one\n"
"hello\nworld".each {|s| p s}
print "Example two\n"
"hello\nworld".each('l') {|s| p s}
print "Example three\n"
"hello\n\n\nworld".each('') {|s| p s}

produces:

Example one
"hello\n"
"world"
Example two
"hel"
"l"
"o\nworl"
"d"
Example three
"hello\n\n\n"
"world"

Overloads:

  • #each(separator = $/) {|substr| ... } ⇒ String

    Yields:

    • (substr)

    Returns:

  • #each_line(separator = $/) {|substr| ... } ⇒ String

    Yields:

    • (substr)

    Returns:



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# File 'string.c', line 3734

static VALUE
rb_str_each_line(argc, argv, str)
int argc;

#each_byte {|fixnum| ... } ⇒ String

Passes each byte in str to the given block.

"hello".each_byte {|c| print c, ' ' }

produces:

104 101 108 108 111

Yields:

  • (fixnum)

Returns:



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# File 'string.c', line 3816

static VALUE
rb_str_each_byte(str)
VALUE str;

#each_char {|cstr| ... } ⇒ String

Passes each character in str to the given block.

"hello".each_char {|c| print c, ' ' }

produces:

h e l l o

Yields:

  • (cstr)

Returns:



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# File 'string.c', line 3856

static VALUE
rb_str_each_char(VALUE str)
{
    int i, len, n;
    const char *ptr;

    RETURN_ENUMERATOR(str, 0, 0);
    str = rb_str_new4(str);
    ptr = RSTRING(str)->ptr;
    len = RSTRING(str)->len;
    for (i = 0; i < len; i += n) {
        n = mbclen(ptr[i]);
        rb_yield(rb_str_substr(str, i, n));
    }
    return str;
}

#each(separator = $/) {|substr| ... } ⇒ String #each_line(separator = $/) {|substr| ... } ⇒ String

Splits str using the supplied parameter as the record separator ($/ by default), passing each substring in turn to the supplied block. If a zero-length record separator is supplied, the string is split into paragraphs delimited by multiple successive newlines.

print "Example one\n"
"hello\nworld".each {|s| p s}
print "Example two\n"
"hello\nworld".each('l') {|s| p s}
print "Example three\n"
"hello\n\n\nworld".each('') {|s| p s}

produces:

Example one
"hello\n"
"world"
Example two
"hel"
"l"
"o\nworl"
"d"
Example three
"hello\n\n\n"
"world"

Overloads:

  • #each(separator = $/) {|substr| ... } ⇒ String

    Yields:

    • (substr)

    Returns:

  • #each_line(separator = $/) {|substr| ... } ⇒ String

    Yields:

    • (substr)

    Returns:



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# File 'string.c', line 3734

static VALUE
rb_str_each_line(argc, argv, str)
int argc;

#empty? ⇒ Boolean

Returns true if str has a length of zero.

"hello".empty?   #=> false
"".empty?        #=> true

Returns:

  • (Boolean) 


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# File 'string.c', line 372

static VALUE
rb_str_empty(str)
VALUE str;

#end_with?([suffix]) ⇒ Boolean

Returns true if str ends with the suffix given.

Returns:

  • (Boolean) 


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# File 'string.c', line 4862

static VALUE
rb_str_end_with(argc, argv, str)
int argc;

#eql?(other) ⇒ Boolean

Two strings are equal if the have the same length and content.

Returns:

  • (Boolean) 


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# File 'string.c', line 977

static VALUE
rb_str_eql(str1, str2)
VALUE str1, str2;

#gsub(pattern, replacement) ⇒ String #gsub(pattern) {|match| ... } ⇒ String

Returns a copy of str with all occurrences of pattern replaced with either replacement or the value of the block. The pattern will typically be a Regexp; if it is a String then no regular expression metacharacters will be interpreted (that is /\d/ will match a digit, but '\d' will match a backslash followed by a ‘d’).

If a string is used as the replacement, special variables from the match (such as $& and $1) cannot be substituted into it, as substitution into the string occurs before the pattern match starts. However, the sequences \1, \2, and so on may be used to interpolate successive groups in the match.

In the block form, the current match string is passed in as a parameter, and variables such as $1, $2, $`, $&, and $' will be set appropriately. The value returned by the block will be substituted for the match on each call.

The result inherits any tainting in the original string or any supplied replacement string.

"hello".gsub(/[aeiou]/, '*')              #=> "h*ll*"
"hello".gsub(/([aeiou])/, '<\1>')         #=> "h<e>ll<o>"
"hello".gsub(/./) {|s| s[0].to_s + ' '}   #=> "104 101 108 108 111 "

Overloads:



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# File 'string.c', line 2277

static VALUE
rb_str_gsub(argc, argv, str)
int argc;

#gsub!(pattern, replacement) ⇒ String? #gsub!(pattern) {|match| ... } ⇒ String?

Performs the substitutions of String#gsub in place, returning str, or nil if no substitutions were performed.

Overloads:

  • #gsub!(pattern, replacement) ⇒ String?

    Returns:

  • #gsub!(pattern) {|match| ... } ⇒ String?

    Yields:

    Returns:



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# File 'string.c', line 2236

static VALUE
rb_str_gsub_bang(argc, argv, str)
int argc;

#hash ⇒ Fixnum

Return a hash based on the string’s length and content.

Returns:



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# File 'string.c', line 912

static VALUE
rb_str_hash_m(str)
VALUE str;

#hex ⇒ Integer

Treats leading characters from str as a string of hexadecimal digits (with an optional sign and an optional 0x) and returns the corresponding number. Zero is returned on error.

"0x0a".hex     #=> 10
"-1234".hex    #=> -4660
"0".hex        #=> 0
"wombat".hex   #=> 0

Returns:



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# File 'string.c', line 4438

static VALUE
rb_str_hex(str)
VALUE str;

#include?(other_str) ⇒ Boolean #include?(fixnum) ⇒ Boolean

Returns true if str contains the given string or character.

"hello".include? "lo"   #=> true
"hello".include? "ol"   #=> false
"hello".include? ?h     #=> true

Overloads:

  • #include?(other_str) ⇒ Boolean

    Returns:

    • (Boolean)
  • #include?(fixnum) ⇒ Boolean

    Returns:

    • (Boolean) 


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# File 'string.c', line 2500

static VALUE
rb_str_include(str, arg)
VALUE str, arg;

#index(substring[, offset]) ⇒ Fixnum? #index(fixnum[, offset]) ⇒ Fixnum? #index(regexp[, offset]) ⇒ Fixnum?

Returns the index of the first occurrence of the given substring, character (fixnum), or pattern (regexp) in str. Returns nil if not found. If the second parameter is present, it specifies the position in the string to begin the search.

"hello".index('e')             #=> 1
"hello".index('lo')            #=> 3
"hello".index('a')             #=> nil
"hello".index(101)             #=> 1
"hello".index(/[aeiou]/, -3)   #=> 4

Overloads:

  • #index(substring[, offset]) ⇒ Fixnum?

    Returns:

  • #index(fixnum[, offset]) ⇒ Fixnum?

    Returns:

  • #index(regexp[, offset]) ⇒ Fixnum?

    Returns:



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# File 'string.c', line 1115

static VALUE
rb_str_index_m(argc, argv, str)
int argc;

#replace(other_str) ⇒ String

Replaces the contents and taintedness of str with the corresponding values in other_str.

s = "hello"         #=> "hello"
s.replace "world"   #=> "world"

Returns:



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# File 'string.c', line 2298

static VALUE
rb_str_replace(str, str2)
VALUE str, str2;

#insert(index, other_str) ⇒ String

Inserts other_str before the character at the given index, modifying str. Negative indices count from the end of the string, and insert after the given character. The intent is insert aString so that it starts at the given index.

"abcd".insert(0, 'X')    #=> "Xabcd"
"abcd".insert(3, 'X')    #=> "abcXd"
"abcd".insert(4, 'X')    #=> "abcdX"
"abcd".insert(-3, 'X')   #=> "abXcd"
"abcd".insert(-1, 'X')   #=> "abcdX"

Returns:



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# File 'string.c', line 1868

static VALUE
rb_str_insert(str, idx, str2)
VALUE str, idx, str2;

#inspect ⇒ String

Returns a printable version of str, with special characters escaped.

str = "hello"
str[3] = 8
str.inspect       #=> "hel\010o"

Returns:



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# File 'string.c', line 2615

VALUE
rb_str_inspect(str)
VALUE str;

#intern ⇒ Object #to_sym ⇒ Object

Returns the Symbol corresponding to str, creating the symbol if it did not previously exist. See Symbol#id2name.

"Koala".intern         #=> :Koala
s = 'cat'.to_sym       #=> :cat
s == :cat              #=> true
s = '@cat'.to_sym      #=> :@cat
s == :@cat             #=> true

This can also be used to create symbols that cannot be represented using the :xxx notation.

'cat and dog'.to_sym   #=> :"cat and dog"



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# File 'string.c', line 4519

VALUE
rb_str_intern(s)
VALUE s;

#length ⇒ Integer

Returns the length of str.

Returns:



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# File 'string.c', line 355

static VALUE
rb_str_length(str)
VALUE str;

#each(separator = $/) {|substr| ... } ⇒ String #each_line(separator = $/) {|substr| ... } ⇒ String

Splits str using the supplied parameter as the record separator ($/ by default), passing each substring in turn to the supplied block. If a zero-length record separator is supplied, the string is split into paragraphs delimited by multiple successive newlines.

print "Example one\n"
"hello\nworld".each {|s| p s}
print "Example two\n"
"hello\nworld".each('l') {|s| p s}
print "Example three\n"
"hello\n\n\nworld".each('') {|s| p s}

produces:

Example one
"hello\n"
"world"
Example two
"hel"
"l"
"o\nworl"
"d"
Example three
"hello\n\n\n"
"world"

Overloads:

  • #each(separator = $/) {|substr| ... } ⇒ String

    Yields:

    • (substr)

    Returns:

  • #each_line(separator = $/) {|substr| ... } ⇒ String

    Yields:

    • (substr)

    Returns:



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# File 'string.c', line 3734

static VALUE
rb_str_each_line(argc, argv, str)
int argc;

#ljust(integer, padstr = ' ') ⇒ String

If integer is greater than the length of str, returns a new String of length integer with str left justified and padded with padstr; otherwise, returns str.

"hello".ljust(4)            #=> "hello"
"hello".ljust(20)           #=> "hello               "
"hello".ljust(20, '1234')   #=> "hello123412341234123"

Returns:



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# File 'string.c', line 4685

static VALUE
rb_str_ljust(argc, argv, str)
int argc;

#lstrip ⇒ String

Returns a copy of str with leading whitespace removed. See also String#rstrip and String#strip.

"  hello  ".lstrip   #=> "hello  "
"hello".lstrip       #=> "hello"

Returns:



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# File 'string.c', line 4198

static VALUE
rb_str_lstrip(str)
VALUE str;

#lstrip! ⇒ self?

Removes leading whitespace from str, returning nil if no change was made. See also String#rstrip! and String#strip!.

"  hello  ".lstrip   #=> "hello  "
"hello".lstrip!      #=> nil

Returns:

  • (self, nil) 


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# File 'string.c', line 4164

static VALUE
rb_str_lstrip_bang(str)
VALUE str;

#match(pattern) ⇒ MatchData?

Converts pattern to a Regexp (if it isn’t already one), then invokes its match method on str.

'hello'.match('(.)\1')      #=> #<MatchData:0x401b3d30>
'hello'.match('(.)\1')[0]   #=> "ll"
'hello'.match(/(.)\1/)[0]   #=> "ll"
'hello'.match('xx')         #=> nil

Returns:



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# File 'string.c', line 1346

static VALUE
rb_str_match_m(str, re)
VALUE str, re;

#succ ⇒ String #next ⇒ String

Returns the successor to str. The successor is calculated by incrementing characters starting from the rightmost alphanumeric (or the rightmost character if there are no alphanumerics) in the string. Incrementing a digit always results in another digit, and incrementing a letter results in another letter of the same case. Incrementing nonalphanumerics uses the underlying character set’s collating sequence.

If the increment generates a “carry,” the character to the left of it is incremented. This process repeats until there is no carry, adding an additional character if necessary.

"abcd".succ        #=> "abce"
"THX1138".succ     #=> "THX1139"
"<<koala>>".succ   #=> "<<koalb>>"
"1999zzz".succ     #=> "2000aaa"
"ZZZ9999".succ     #=> "AAAA0000"
"***".succ         #=> "**+"

Overloads:



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# File 'string.c', line 1404

static VALUE
rb_str_succ(orig)
VALUE orig;

#succ! ⇒ String #next! ⇒ String

Equivalent to String#succ, but modifies the receiver in place.

Overloads:



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# File 'string.c', line 1456

static VALUE
rb_str_succ_bang(str)
VALUE str;

#oct ⇒ Integer

Treats leading characters of str as a string of octal digits (with an optional sign) and returns the corresponding number. Returns 0 if the conversion fails.

"123".oct       #=> 83
"-377".oct      #=> -255
"bad".oct       #=> 0
"0377bad".oct   #=> 255

Returns:



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# File 'string.c', line 4460

static VALUE
rb_str_oct(str)
VALUE str;

#partition(sep) ⇒ Array

Searches the string for sep and returns the part before it, the sep, and the part after it. If sep is not found, returns str and two empty strings. If no argument is given, Enumerable#partition is called.

"hello".partition("l")         #=> ["he", "l", "lo"]
"hello".partition("x")         #=> ["hello", "", ""]

Returns:



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# File 'string.c', line 4753

static VALUE
rb_str_partition(argc, argv, str)
int argc;

#replace(other_str) ⇒ String

Replaces the contents and taintedness of str with the corresponding values in other_str.

s = "hello"         #=> "hello"
s.replace "world"   #=> "world"

Returns:



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# File 'string.c', line 2298

static VALUE
rb_str_replace(str, str2)
VALUE str, str2;

#reverse ⇒ String

Returns a new string with the characters from str in reverse order.

"stressed".reverse   #=> "desserts"

Returns:



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# File 'string.c', line 2465

static VALUE
rb_str_reverse(str)
VALUE str;

#reverse! ⇒ String

Reverses str in place.

Returns:



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# File 'string.c', line 2435

static VALUE
rb_str_reverse_bang(str)
VALUE str;

#rindex(substring[, fixnum]) ⇒ Fixnum? #rindex(fixnum[, fixnum]) ⇒ Fixnum? #rindex(regexp[, fixnum]) ⇒ Fixnum?

Returns the index of the last occurrence of the given substring, character (fixnum), or pattern (regexp) in str. Returns nil if not found. If the second parameter is present, it specifies the position in the string to end the search—characters beyond this point will not be considered.

"hello".rindex('e')             #=> 1
"hello".rindex('l')             #=> 3
"hello".rindex('a')             #=> nil
"hello".rindex(101)             #=> 1
"hello".rindex(/[aeiou]/, -2)   #=> 1

Overloads:

  • #rindex(substring[, fixnum]) ⇒ Fixnum?

    Returns:

  • #rindex(fixnum[, fixnum]) ⇒ Fixnum?

    Returns:

  • #rindex(regexp[, fixnum]) ⇒ Fixnum?

    Returns:



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# File 'string.c', line 1228

static VALUE
rb_str_rindex_m(argc, argv, str)
int argc;

#rjust(integer, padstr = ' ') ⇒ String

If integer is greater than the length of str, returns a new String of length integer with str right justified and padded with padstr; otherwise, returns str.

"hello".rjust(4)            #=> "hello"
"hello".rjust(20)           #=> "               hello"
"hello".rjust(20, '1234')   #=> "123412341234123hello"

Returns:



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# File 'string.c', line 4708

static VALUE
rb_str_rjust(argc, argv, str)
int argc;

#rpartition(sep) ⇒ Array

Searches sep in the string from the end of the string, and returns the part before it, the sep, and the part after it. If sep is not found, returns two empty strings and str.

"hello".rpartition("l")         #=> ["hel", "l", "o"]
"hello".rpartition("x")         #=> ["", "", "hello"]

Returns:



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# File 'string.c', line 4800

static VALUE
rb_str_rpartition(str, sep)
VALUE str;

#rstrip ⇒ String

Returns a copy of str with trailing whitespace removed. See also String#lstrip and String#strip.

"  hello  ".rstrip   #=> "  hello"
"hello".rstrip       #=> "hello"

Returns:



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# File 'string.c', line 4257

static VALUE
rb_str_rstrip(str)
VALUE str;

#rstrip! ⇒ self?

Removes trailing whitespace from str, returning nil if no change was made. See also String#lstrip! and String#strip!.

"  hello  ".rstrip   #=> "  hello"
"hello".rstrip!      #=> nil

Returns:

  • (self, nil) 


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# File 'string.c', line 4220

static VALUE
rb_str_rstrip_bang(str)
VALUE str;

#scan(pattern) ⇒ Array #scan(pattern) {|match, ...| ... } ⇒ String

Both forms iterate through str, matching the pattern (which may be a Regexp or a String). For each match, a result is generated and either added to the result array or passed to the block. If the pattern contains no groups, each individual result consists of the matched string, $&. If the pattern contains groups, each individual result is itself an array containing one entry per group.

a = "cruel world"
a.scan(/\w+/)        #=> ["cruel", "world"]
a.scan(/.../)        #=> ["cru", "el ", "wor"]
a.scan(/(...)/)      #=> [["cru"], ["el "], ["wor"]]
a.scan(/(..)(..)/)   #=> [["cr", "ue"], ["l ", "wo"]]

And the block form:

a.scan(/\w+/) {|w| print "<<#{w}>> " }
print "\n"
a.scan(/(.)(.)/) {|x,y| print y, x }
print "\n"

produces:

<<cruel>> <<world>>
rceu lowlr

Overloads:



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# File 'string.c', line 4375

static VALUE
rb_str_scan(str, pat)
VALUE str, pat;

#length ⇒ Integer

Returns the length of str.

Returns:



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# File 'string.c', line 355

static VALUE
rb_str_length(str)
VALUE str;

#[](fixnum) ⇒ Fixnum? #[](fixnum, fixnum) ⇒ String? #[](range) ⇒ String? #[](regexp) ⇒ String? #[](regexp, fixnum) ⇒ String? #[](other_str) ⇒ String? #slice(fixnum) ⇒ Fixnum? #slice(fixnum, fixnum) ⇒ String? #slice(range) ⇒ String? #slice(regexp) ⇒ String? #slice(regexp, fixnum) ⇒ String? #slice(other_str) ⇒ String?

Element Reference—If passed a single Fixnum, returns the code of the character at that position. If passed two Fixnum objects, returns a substring starting at the offset given by the first, and a length given by the second. If given a range, a substring containing characters at offsets given by the range is returned. In all three cases, if an offset is negative, it is counted from the end of str. Returns nil if the initial offset falls outside the string, the length is negative, or the beginning of the range is greater than the end.

If a Regexp is supplied, the matching portion of str is returned. If a numeric parameter follows the regular expression, that component of the MatchData is returned instead. If a String is given, that string is returned if it occurs in str. In both cases, nil is returned if there is no match.

a = "hello there"
a[1]                   #=> 101
a[1,3]                 #=> "ell"
a[1..3]                #=> "ell"
a[-3,2]                #=> "er"
a[-4..-2]              #=> "her"
a[12..-1]              #=> nil
a[-2..-4]              #=> ""
a[/[aeiou](.)\1/]      #=> "ell"
a[/[aeiou](.)\1/, 0]   #=> "ell"
a[/[aeiou](.)\1/, 1]   #=> "l"
a[/[aeiou](.)\1/, 2]   #=> nil
a["lo"]                #=> "lo"
a["bye"]               #=> nil

Overloads:



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# File 'string.c', line 1638

static VALUE
rb_str_aref_m(argc, argv, str)
int argc;

#slice!(fixnum) ⇒ Fixnum? #slice!(fixnum, fixnum) ⇒ String? #slice!(range) ⇒ String? #slice!(regexp) ⇒ String? #slice!(other_str) ⇒ String?

Deletes the specified portion from str, and returns the portion deleted. The forms that take a Fixnum will raise an IndexError if the value is out of range; the Range form will raise a RangeError, and the Regexp and String forms will silently ignore the assignment.

string = "this is a string"
string.slice!(2)        #=> 105
string.slice!(3..6)     #=> " is "
string.slice!(/s.*t/)   #=> "sa st"
string.slice!("r")      #=> "r"
string                  #=> "thing"

Overloads:



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# File 'string.c', line 1906

static VALUE
rb_str_slice_bang(argc, argv, str)
int argc;

#split(pattern = $;, [limit]) ⇒ Array

Divides str into substrings based on a delimiter, returning an array of these substrings.

If pattern is a String, then its contents are used as the delimiter when splitting str. If pattern is a single space, str is split on whitespace, with leading whitespace and runs of contiguous whitespace characters ignored.

If pattern is a Regexp, str is divided where the pattern matches. Whenever the pattern matches a zero-length string, str is split into individual characters.

If pattern is omitted, the value of $; is used. If $; is nil (which is the default), str is split on whitespace as if ‘ ’ were specified.

If the limit parameter is omitted, trailing null fields are suppressed. If limit is a positive number, at most that number of fields will be returned (if limit is 1, the entire string is returned as the only entry in an array). If negative, there is no limit to the number of fields returned, and trailing null fields are not suppressed.

" now's  the time".split        #=> ["now's", "the", "time"]
" now's  the time".split(' ')   #=> ["now's", "the", "time"]
" now's  the time".split(/ /)   #=> ["", "now's", "", "the", "time"]
"1, 2.34,56, 7".split(%r{,\s*}) #=> ["1", "2.34", "56", "7"]
"hello".split(//)               #=> ["h", "e", "l", "l", "o"]
"hello".split(//, 3)            #=> ["h", "e", "llo"]
"hi mom".split(%r{\s*})         #=> ["h", "i", "m", "o", "m"]

"mellow yellow".split("ello")   #=> ["m", "w y", "w"]
"1,2,,3,4,,".split(',')         #=> ["1", "2", "", "3", "4"]
"1,2,,3,4,,".split(',', 4)      #=> ["1", "2", "", "3,4,,"]
"1,2,,3,4,,".split(',', -4)     #=> ["1", "2", "", "3", "4", "", ""]

Returns:



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# File 'string.c', line 3527

static VALUE
rb_str_split_m(argc, argv, str)
int argc;

#squeeze([other_str]) ⇒ String

Builds a set of characters from the other_str parameter(s) using the procedure described for String#count. Returns a new string where runs of the same character that occur in this set are replaced by a single character. If no arguments are given, all runs of identical characters are replaced by a single character.

"yellow moon".squeeze                  #=> "yelow mon"
"  now   is  the".squeeze(" ")         #=> " now is the"
"putters shoot balls".squeeze("m-z")   #=> "puters shot balls"

Returns:



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# File 'string.c', line 3384

static VALUE
rb_str_squeeze(argc, argv, str)
int argc;

#squeeze!([other_str]) ⇒ String?

Squeezes str in place, returning either str, or nil if no changes were made.

Returns:



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# File 'string.c', line 3320

static VALUE
rb_str_squeeze_bang(argc, argv, str)
int argc;

#start_with?([prefix]) ⇒ Boolean

Returns true if str starts with the prefix given.

Returns:

  • (Boolean) 


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# File 'string.c', line 4835

static VALUE
rb_str_start_with(argc, argv, str)
int argc;

#strip ⇒ String

Returns a copy of str with leading and trailing whitespace removed.

"    hello    ".strip   #=> "hello"
"\tgoodbye\r\n".strip   #=> "goodbye"

Returns:



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# File 'string.c', line 4297

static VALUE
rb_str_strip(str)
VALUE str;

#strip! ⇒ String?

Removes leading and trailing whitespace from str. Returns nil if str was not altered.

Returns:



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# File 'string.c', line 4275

static VALUE
rb_str_strip_bang(str)
VALUE str;

#sub(pattern, replacement) ⇒ String #sub(pattern) {|match| ... } ⇒ String

Returns a copy of str with the first occurrence of pattern replaced with either replacement or the value of the block. The pattern will typically be a Regexp; if it is a String then no regular expression metacharacters will be interpreted (that is /\d/ will match a digit, but '\d' will match a backslash followed by a ‘d’).

If the method call specifies replacement, special variables such as $& will not be useful, as substitution into the string occurs before the pattern match starts. However, the sequences \1, \2, etc., may be used.

In the block form, the current match string is passed in as a parameter, and variables such as $1, $2, $`, $&, and $' will be set appropriately. The value returned by the block will be substituted for the match on each call.

The result inherits any tainting in the original string or any supplied replacement string.

"hello".sub(/[aeiou]/, '*')               #=> "h*llo"
"hello".sub(/([aeiou])/, '<\1>')          #=> "h<e>llo"
"hello".sub(/./) {|s| s[0].to_s + ' ' }   #=> "104 ello"

Overloads:



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# File 'string.c', line 2088

static VALUE
rb_str_sub(argc, argv, str)
int argc;

#sub!(pattern, replacement) ⇒ String? #sub!(pattern) {|match| ... } ⇒ String?

Performs the substitutions of String#sub in place, returning str, or nil if no substitutions were performed.

Overloads:

  • #sub!(pattern, replacement) ⇒ String?

    Returns:

  • #sub!(pattern) {|match| ... } ⇒ String?

    Yields:

    Returns:



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# File 'string.c', line 1994

static VALUE
rb_str_sub_bang(argc, argv, str)
int argc;

#succ ⇒ String #next ⇒ String

Returns the successor to str. The successor is calculated by incrementing characters starting from the rightmost alphanumeric (or the rightmost character if there are no alphanumerics) in the string. Incrementing a digit always results in another digit, and incrementing a letter results in another letter of the same case. Incrementing nonalphanumerics uses the underlying character set’s collating sequence.

If the increment generates a “carry,” the character to the left of it is incremented. This process repeats until there is no carry, adding an additional character if necessary.

"abcd".succ        #=> "abce"
"THX1138".succ     #=> "THX1139"
"<<koala>>".succ   #=> "<<koalb>>"
"1999zzz".succ     #=> "2000aaa"
"ZZZ9999".succ     #=> "AAAA0000"
"***".succ         #=> "**+"

Overloads:



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# File 'string.c', line 1404

static VALUE
rb_str_succ(orig)
VALUE orig;

#succ! ⇒ String #next! ⇒ String

Equivalent to String#succ, but modifies the receiver in place.

Overloads:



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# File 'string.c', line 1456

static VALUE
rb_str_succ_bang(str)
VALUE str;

#sum(n = 16) ⇒ Integer

Returns a basic n-bit checksum of the characters in str, where n is the optional Fixnum parameter, defaulting to 16. The result is simply the sum of the binary value of each character in str modulo 2n - 1. This is not a particularly good checksum.

Returns:



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# File 'string.c', line 4550

static VALUE
rb_str_sum(argc, argv, str)
int argc;

#swapcase ⇒ String

Returns a copy of str with uppercase alphabetic characters converted to lowercase and lowercase characters converted to uppercase.

"Hello".swapcase          #=> "hELLO"
"cYbEr_PuNk11".swapcase   #=> "CyBeR_pUnK11"

Returns:



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# File 'string.c', line 3010

static VALUE
rb_str_swapcase(str)
VALUE str;

#swapcase! ⇒ String?

Equivalent to String#swapcase, but modifies the receiver in place, returning str, or nil if no changes were made.

Returns:



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# File 'string.c', line 2970

static VALUE
rb_str_swapcase_bang(str)
VALUE str;

#to_f ⇒ Float

Returns the result of interpreting leading characters in str as a floating point number. Extraneous characters past the end of a valid number are ignored. If there is not a valid number at the start of str, 0.0 is returned. This method never raises an exception.

"123.45e1".to_f        #=> 1234.5
"45.67 degrees".to_f   #=> 45.67
"thx1138".to_f         #=> 0.0

Returns:



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# File 'string.c', line 2575

static VALUE
rb_str_to_f(str)
VALUE str;

#to_i(base = 10) ⇒ Integer

Returns the result of interpreting leading characters in str as an integer base base (between 2 and 36). Extraneous characters past the end of a valid number are ignored. If there is not a valid number at the start of str, 0 is returned. This method never raises an exception.

"12345".to_i             #=> 12345
"99 red balloons".to_i   #=> 99
"0a".to_i                #=> 0
"0a".to_i(16)            #=> 10
"hello".to_i             #=> 0
"1100101".to_i(2)        #=> 101
"1100101".to_i(8)        #=> 294977
"1100101".to_i(10)       #=> 1100101
"1100101".to_i(16)       #=> 17826049

Returns:



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# File 'string.c', line 2541

static VALUE
rb_str_to_i(argc, argv, str)
int argc;

#to_s ⇒ String #to_str ⇒ String

Returns the receiver.

Overloads:



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# File 'string.c', line 2591

static VALUE
rb_str_to_s(str)
VALUE str;

#to_s ⇒ String #to_str ⇒ String

Returns the receiver.

Overloads:



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# File 'string.c', line 2591

static VALUE
rb_str_to_s(str)
VALUE str;

#intern ⇒ Object #to_sym ⇒ Object

Returns the Symbol corresponding to str, creating the symbol if it did not previously exist. See Symbol#id2name.

"Koala".intern         #=> :Koala
s = 'cat'.to_sym       #=> :cat
s == :cat              #=> true
s = '@cat'.to_sym      #=> :@cat
s == :@cat             #=> true

This can also be used to create symbols that cannot be represented using the :xxx notation.

'cat and dog'.to_sym   #=> :"cat and dog"



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# File 'string.c', line 4519

VALUE
rb_str_intern(s)
VALUE s;

#tr(from_str, to_str) ⇒ String

Returns a copy of str with the characters in from_str replaced by the corresponding characters in to_str. If to_str is shorter than from_str, it is padded with its last character. Both strings may use the c1–c2 notation to denote ranges of characters, and from_str may start with a ^, which denotes all characters except those listed.

"hello".tr('aeiou', '*')    #=> "h*ll*"
"hello".tr('^aeiou', '*')   #=> "*e**o"
"hello".tr('el', 'ip')      #=> "hippo"
"hello".tr('a-y', 'b-z')    #=> "ifmmp"

Returns:



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# File 'string.c', line 3192

static VALUE
rb_str_tr(str, src, repl)
VALUE str, src, repl;

#tr!(from_str, to_str) ⇒ String?

Translates str in place, using the same rules as String#tr. Returns str, or nil if no changes were made.

Returns:



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# File 'string.c', line 3167

static VALUE
rb_str_tr_bang(str, src, repl)
VALUE str, src, repl;

#tr_s(from_str, to_str) ⇒ String

Processes a copy of str as described under String#tr, then removes duplicate characters in regions that were affected by the translation.

"hello".tr_s('l', 'r')     #=> "hero"
"hello".tr_s('el', '*')    #=> "h*o"
"hello".tr_s('el', 'hx')   #=> "hhxo"

Returns:



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# File 'string.c', line 3425

static VALUE
rb_str_tr_s(str, src, repl)
VALUE str, src, repl;

#tr_s!(from_str, to_str) ⇒ String?

Performs String#tr_s processing on str in place, returning str, or nil if no changes were made.

Returns:



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# File 'string.c', line 3404

static VALUE
rb_str_tr_s_bang(str, src, repl)
VALUE str, src, repl;

#unpack(format) ⇒ Array

Decodes str (which may contain binary data) according to the format string, returning an array of each value extracted. The format string consists of a sequence of single-character directives, summarized in the table at the end of this entry. Each directive may be followed by a number, indicating the number of times to repeat with this directive. An asterisk (“*”) will use up all remaining elements. The directives sSiIlL may each be followed by an underscore (“_”) to use the underlying platform’s native size for the specified type; otherwise, it uses a platform-independent consistent size. Spaces are ignored in the format string. See also Array#pack.

"abc \0\0abc \0\0".unpack('A6Z6')   #=> ["abc", "abc "]
"abc \0\0".unpack('a3a3')           #=> ["abc", " \000\000"]
"abc \0abc \0".unpack('Z*Z*')       #=> ["abc ", "abc "]
"aa".unpack('b8B8')                 #=> ["10000110", "01100001"]
"aaa".unpack('h2H2c')               #=> ["16", "61", 97]
"\xfe\xff\xfe\xff".unpack('sS')     #=> [-2, 65534]
"now=20is".unpack('M*')             #=> ["now is"]
"whole".unpack('xax2aX2aX1aX2a')    #=> ["h", "e", "l", "l", "o"]

This table summarizes the various formats and the Ruby classes returned by each.

Format | Returns | Function
-------+---------+-----------------------------------------
  A    | String  | with trailing nulls and spaces removed
-------+---------+-----------------------------------------
  a    | String  | string
-------+---------+-----------------------------------------
  B    | String  | extract bits from each character (msb first)
-------+---------+-----------------------------------------
  b    | String  | extract bits from each character (lsb first)
-------+---------+-----------------------------------------
  C    | Fixnum  | extract a character as an unsigned integer
-------+---------+-----------------------------------------
  c    | Fixnum  | extract a character as an integer
-------+---------+-----------------------------------------
  d,D  | Float   | treat sizeof(double) characters as
       |         | a native double
-------+---------+-----------------------------------------
  E    | Float   | treat sizeof(double) characters as
       |         | a double in little-endian byte order
-------+---------+-----------------------------------------
  e    | Float   | treat sizeof(float) characters as
       |         | a float in little-endian byte order
-------+---------+-----------------------------------------
  f,F  | Float   | treat sizeof(float) characters as
       |         | a native float
-------+---------+-----------------------------------------
  G    | Float   | treat sizeof(double) characters as
       |         | a double in network byte order
-------+---------+-----------------------------------------
  g    | Float   | treat sizeof(float) characters as a
       |         | float in network byte order
-------+---------+-----------------------------------------
  H    | String  | extract hex nibbles from each character
       |         | (most significant first)
-------+---------+-----------------------------------------
  h    | String  | extract hex nibbles from each character
       |         | (least significant first)
-------+---------+-----------------------------------------
  I    | Integer | treat sizeof(int) (modified by _)
       |         | successive characters as an unsigned
       |         | native integer
-------+---------+-----------------------------------------
  i    | Integer | treat sizeof(int) (modified by _)
       |         | successive characters as a signed
       |         | native integer
-------+---------+-----------------------------------------
  L    | Integer | treat four (modified by _) successive
       |         | characters as an unsigned native
       |         | long integer
-------+---------+-----------------------------------------
  l    | Integer | treat four (modified by _) successive
       |         | characters as a signed native
       |         | long integer
-------+---------+-----------------------------------------
  M    | String  | quoted-printable
-------+---------+-----------------------------------------
  m    | String  | base64-encoded
-------+---------+-----------------------------------------
  N    | Integer | treat four characters as an unsigned
       |         | long in network byte order
-------+---------+-----------------------------------------
  n    | Fixnum  | treat two characters as an unsigned
       |         | short in network byte order
-------+---------+-----------------------------------------
  P    | String  | treat sizeof(char *) characters as a
       |         | pointer, and  return \emph{len} characters
       |         | from the referenced location
-------+---------+-----------------------------------------
  p    | String  | treat sizeof(char *) characters as a
       |         | pointer to a  null-terminated string
-------+---------+-----------------------------------------
  Q    | Integer | treat 8 characters as an unsigned
       |         | quad word (64 bits)
-------+---------+-----------------------------------------
  q    | Integer | treat 8 characters as a signed
       |         | quad word (64 bits)
-------+---------+-----------------------------------------
  S    | Fixnum  | treat two (different if _ used)
       |         | successive characters as an unsigned
       |         | short in native byte order
-------+---------+-----------------------------------------
  s    | Fixnum  | Treat two (different if _ used)
       |         | successive characters as a signed short
       |         | in native byte order
-------+---------+-----------------------------------------
  U    | Integer | UTF-8 characters as unsigned integers
-------+---------+-----------------------------------------
  u    | String  | UU-encoded
-------+---------+-----------------------------------------
  V    | Fixnum  | treat four characters as an unsigned
       |         | long in little-endian byte order
-------+---------+-----------------------------------------
  v    | Fixnum  | treat two characters as an unsigned
       |         | short in little-endian byte order
-------+---------+-----------------------------------------
  w    | Integer | BER-compressed integer (see Array.pack)
-------+---------+-----------------------------------------
  X    | ---     | skip backward one character
-------+---------+-----------------------------------------
  x    | ---     | skip forward one character
-------+---------+-----------------------------------------
  Z    | String  | with trailing nulls removed
       |         | upto first null with *
-------+---------+-----------------------------------------
  @    | ---     | skip to the offset given by the
       |         | length argument
-------+---------+-----------------------------------------

Returns:



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# File 'pack.c', line 1303

static VALUE
pack_unpack(str, fmt)
VALUE str, fmt;

#upcase ⇒ String

Returns a copy of str with all lowercase letters replaced with their uppercase counterparts. The operation is locale insensitive—only characters “a” to “z” are affected.

"hEllO".upcase   #=> "HELLO"

Returns:



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# File 'string.c', line 2835

static VALUE
rb_str_upcase(str)
VALUE str;

#upcase! ⇒ String?

Upcases the contents of str, returning nil if no changes were made.

Returns:



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# File 'string.c', line 2799

static VALUE
rb_str_upcase_bang(str)
VALUE str;

#upto(other_str, exclusive = false) {|s| ... } ⇒ String

Iterates through successive values, starting at str and ending at other_str inclusive, passing each value in turn to the block. The String#succ method is used to generate each value. If optional second argument exclusive is omitted or is false, the last value will be included; otherwise it will be excluded.

"a8".upto("b6") {|s| print s, ' ' }
for s in "a8".."b6"
  print s, ' '
end

produces:

a8 a9 b0 b1 b2 b3 b4 b5 b6
a8 a9 b0 b1 b2 b3 b4 b5 b6

Yields:

  • (s)

Returns:



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# File 'string.c', line 1515

static VALUE
rb_str_upto_m(argc, argv, beg)
int argc;