Class: Integer
Overview
******************************************************************
An \Integer object represents an integer value.
You can create an \Integer object explicitly with:
- An {integer literal}[rdoc-ref:syntax/literals.rdoc@Integer+Literals].
You can convert certain objects to Integers with:
- \Method #Integer.
An attempt to add a singleton method to an instance of this class
causes an exception to be raised.
== What's Here
First, what's elsewhere. \Class \Integer:
- Inherits from
{class Numeric}[rdoc-ref:Numeric@What-27s+Here]
and {class Object}[rdoc-ref:Object@What-27s+Here].
- Includes {module Comparable}[rdoc-ref:Comparable@What-27s+Here].
Here, class \Integer provides methods for:
- {}[rdoc-ref:Integer]
- {Comparing}[rdoc-ref:Integer@Comparing]
- {Converting}[rdoc-ref:Integer@Converting]
- {Other}[rdoc-ref:Integer@Other]
===
- #allbits?: Returns whether all bits in +self+ are set.
- #anybits?: Returns whether any bits in +self+ are set.
- #nobits?: Returns whether no bits in +self+ are set.
=== Comparing
- #<: Returns whether +self+ is less than the given value.
- #<=: Returns whether +self+ is less than or equal to the given value.
- #<=>: Returns a number indicating whether +self+ is less than, equal
to, or greater than the given value.
- #== (aliased as #===): Returns whether +self+ is equal to the given
value.
- #>: Returns whether +self+ is greater than the given value.
- #>=: Returns whether +self+ is greater than or equal to the given value.
=== Converting
- ::sqrt: Returns the integer square root of the given value.
- ::try_convert: Returns the given value converted to an \Integer.
- #% (aliased as #modulo): Returns +self+ modulo the given value.
- #&: Returns the bitwise AND of +self+ and the given value.
- #*: Returns the product of +self+ and the given value.
- #**: Returns the value of +self+ raised to the power of the given value.
- #+: Returns the sum of +self+ and the given value.
- #-: Returns the difference of +self+ and the given value.
- #/: Returns the quotient of +self+ and the given value.
- #<<: Returns the value of +self+ after a leftward bit-shift.
- #>>: Returns the value of +self+ after a rightward bit-shift.
- #[]: Returns a slice of bits from +self+.
- #^: Returns the bitwise EXCLUSIVE OR of +self+ and the given value.
- #|: Returns the bitwise OR of +self+ and the given value.
- #ceil: Returns the smallest number greater than or equal to +self+.
- #chr: Returns a 1-character string containing the character
represented by the value of +self+.
- #digits: Returns an array of integers representing the base-radix digits
of +self+.
- #div: Returns the integer result of dividing +self+ by the given value.
- #divmod: Returns a 2-element array containing the quotient and remainder
results of dividing +self+ by the given value.
- #fdiv: Returns the Float result of dividing +self+ by the given value.
- #floor: Returns the greatest number smaller than or equal to +self+.
- #pow: Returns the modular exponentiation of +self+.
- #pred: Returns the integer predecessor of +self+.
- #remainder: Returns the remainder after dividing +self+ by the given value.
- #round: Returns +self+ rounded to the nearest value with the given precision.
- #succ (aliased as #next): Returns the integer successor of +self+.
- #to_f: Returns +self+ converted to a Float.
- #to_s (aliased as #inspect): Returns a string containing the place-value
representation of +self+ in the given radix.
- #truncate: Returns +self+ truncated to the given precision.
=== Other
- #downto: Calls the given block with each integer value from +self+
down to the given value.
- #times: Calls the given block +self+ times with each integer
in <tt>(0..self-1)</tt>.
- #upto: Calls the given block with each integer value from +self+
up to the given value.
Constant Summary collapse
- GMP_VERSION =
The version of loaded GMP.
rb_sprintf("GMP %s", gmp_version)
Class Method Summary collapse
- .sqrt ⇒ Object
-
.try_convert(object) ⇒ Object, ...
If
object
is an Integer object, returnsobject
.
Instance Method Summary collapse
-
#%(other) ⇒ Object
Returns
self
moduloother
as a real number. -
#&(other) ⇒ Integer
Bitwise AND; each bit in the result is 1 if both corresponding bits in
self
andother
are 1, 0 otherwise:. -
#*(numeric) ⇒ Object
Performs multiplication:.
-
#**(numeric) ⇒ Object
Raises
self
to the power ofnumeric
:. -
#+(numeric) ⇒ Object
Performs addition:.
-
#-(numeric) ⇒ Object
Performs subtraction:.
-
#/(numeric) ⇒ Object
Performs division; for integer
numeric
, truncates the result to an integer:. -
#<(other) ⇒ Boolean
Returns
true
if the value ofself
is less than that ofother
:. -
#<<(count) ⇒ Integer
Returns
self
with bits shiftedcount
positions to the left, or to the right ifcount
is negative:. -
#<=(real) ⇒ Boolean
Returns
true
if the value ofself
is less than or equal to that ofother
:. -
#<=>(other) ⇒ -1, ...
Returns:.
-
#==(other) ⇒ Boolean
Returns
true
ifself
is numerically equal toother
;false
otherwise. -
#==(other) ⇒ Boolean
Returns
true
ifself
is numerically equal toother
;false
otherwise. -
#>(other) ⇒ Boolean
Returns
true
if the value ofself
is greater than that ofother
:. -
#>=(real) ⇒ Boolean
Returns
true
if the value ofself
is greater than or equal to that ofother
:. -
#>>(count) ⇒ Integer
Returns
self
with bits shiftedcount
positions to the right, or to the left ifcount
is negative:. -
#[](*, const) ⇒ Object
Returns a slice of bits from
self
. -
#^(other) ⇒ Integer
Bitwise EXCLUSIVE OR; each bit in the result is 1 if the corresponding bits in
self
andother
are different, 0 otherwise:. -
#allbits?(mask) ⇒ Boolean
Returns
true
if all bits that are set (=1) inmask
are also set inself
; returnsfalse
otherwise. -
#anybits?(mask) ⇒ Boolean
Returns
true
if any bit that is set (=1) inmask
is also set inself
; returnsfalse
otherwise. -
#ceil(*args) ⇒ Object
:markup: markdown.
-
#chr(*args) ⇒ Object
Returns a 1-character string containing the character represented by the value of
self
, according to the givenencoding
. -
#coerce(numeric) ⇒ Array
Returns an array with both a
numeric
and aint
represented as Integer objects or Float objects. -
#digits(base = 10) ⇒ Object
Returns an array of integers representing the
base
-radix digits ofself
; the first element of the array represents the least significant digit:. -
#div(numeric) ⇒ Integer
Performs integer division; returns the integer result of dividing
self
bynumeric
:. -
#divmod(other) ⇒ Array
Returns a 2-element array
[q, r]
, where. -
#downto(to) ⇒ Object
Calls the given block with each integer value from
self
down tolimit
; returnsself
:. -
#fdiv(numeric) ⇒ Float
Returns the Float result of dividing
self
bynumeric
:. -
#floor(*args) ⇒ Object
:markup: markdown.
-
#gcd(other_int) ⇒ Integer
Returns the greatest common divisor of the two integers.
-
#gcdlcm(other_int) ⇒ Array
Returns an array with the greatest common divisor and the least common multiple of the two integers, [gcd, lcm].
-
#lcm(other_int) ⇒ Integer
Returns the least common multiple of the two integers.
-
#%(other) ⇒ Object
Returns
self
moduloother
as a real number. - #next ⇒ Object
-
#nobits?(mask) ⇒ Boolean
Returns
true
if no bit that is set (=1) inmask
is also set inself
; returnsfalse
otherwise. -
#pow(*, const) ⇒ Object
Returns (modular) exponentiation as:.
- #pred ⇒ Object
-
#rationalize([eps]) ⇒ Object
Returns the value as a rational.
-
#remainder(other) ⇒ Object
Returns the remainder after dividing
self
byother
. -
#round(ndigits = 0, half: :up) ⇒ Integer
Returns
self
rounded to the nearest value with a precision ofndigits
decimal digits. - #succ ⇒ Object
-
#to_f ⇒ Float
Converts
self
to a Float:. -
#to_r ⇒ Object
Returns the value as a rational.
-
#to_s(base = 10) ⇒ String
(also: #inspect)
Returns a string containing the place-value representation of
self
in radixbase
(in 2..36). -
#truncate(ndigits = 0) ⇒ Integer
Returns
self
truncated (toward zero) to a precision ofndigits
decimal digits. -
#upto(to) ⇒ Object
Calls the given block with each integer value from
self
up tolimit
; returnsself
:. -
#|(other) ⇒ Integer
Bitwise OR; each bit in the result is 1 if either corresponding bit in
self
orother
is 1, 0 otherwise:.
Methods inherited from Numeric
#-@, #abs, #abs2, #angle, #arg, #clone, #denominator, #eql?, #i, #magnitude, #negative?, #nonzero?, #numerator, #phase, #polar, #positive?, #quo, #rect, #rectangular, #singleton_method_added, #step, #to_c, #to_int, #zero?
Methods included from Comparable
Class Method Details
.sqrt ⇒ Object
.try_convert(object) ⇒ Object, ...
If object
is an Integer object, returns object
.
Integer.try_convert(1) # => 1
Otherwise if object
responds to :to_int
, calls object.to_int
and returns the result.
Integer.try_convert(1.25) # => 1
Returns nil
if object
does not respond to :to_int
Integer.try_convert([]) # => nil
Raises an exception unless object.to_int
returns an Integer object.
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# File 'numeric.c', line 6090 static VALUE int_s_try_convert(VALUE self, VALUE num) { return rb_check_integer_type(num); } |
Instance Method Details
#%(other) ⇒ Object
Returns self
modulo other
as a real number.
For integer n
and real number r
, these expressions are equivalent:
n % r
n-r*(n/r).floor
n.divmod(r)[1]
See Numeric#divmod.
Examples:
10 % 2 # => 0
10 % 3 # => 1
10 % 4 # => 2
10 % -2 # => 0
10 % -3 # => -2
10 % -4 # => -2
10 % 3.0 # => 1.0
10 % Rational(3, 1) # => (1/1)
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# File 'numeric.c', line 4378 VALUE rb_int_modulo(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_mod(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_modulo(x, y); } return num_modulo(x, y); } |
#&(other) ⇒ Integer
Bitwise AND; each bit in the result is 1 if both corresponding bits in self
and other
are 1, 0 otherwise:
"%04b" % (0b0101 & 0b0110) # => "0100"
Raises an exception if other
is not an Integer.
Related: Integer#| (bitwise OR), Integer#^ (bitwise EXCLUSIVE OR).
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# File 'numeric.c', line 5034 VALUE rb_int_and(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_and(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_and(x, y); } return Qnil; } |
#*(numeric) ⇒ Object
Performs multiplication:
4 * 2 # => 8
4 * -2 # => -8
-4 * 2 # => -8
4 * 2.0 # => 8.0
4 * Rational(1, 3) # => (4/3)
4 * Complex(2, 0) # => (8+0i)
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# File 'numeric.c', line 4146 VALUE rb_int_mul(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_mul(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_mul(x, y); } return rb_num_coerce_bin(x, y, '*'); } |
#**(numeric) ⇒ Object
Raises self
to the power of numeric
:
2 ** 3 # => 8
2 ** -3 # => (1/8)
-2 ** 3 # => -8
-2 ** -3 # => (-1/8)
2 ** 3.3 # => 9.849155306759329
2 ** Rational(3, 1) # => (8/1)
2 ** Complex(3, 0) # => (8+0i)
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# File 'numeric.c', line 4639 VALUE rb_int_pow(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_pow(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_pow(x, y); } return Qnil; } |
#+(numeric) ⇒ Object
Performs addition:
2 + 2 # => 4
-2 + 2 # => 0
-2 + -2 # => -4
2 + 2.0 # => 4.0
2 + Rational(2, 1) # => (4/1)
2 + Complex(2, 0) # => (4+0i)
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# File 'numeric.c', line 4046 VALUE rb_int_plus(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_plus(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_plus(x, y); } return rb_num_coerce_bin(x, y, '+'); } |
#-(numeric) ⇒ Object
Performs subtraction:
4 - 2 # => 2
-4 - 2 # => -6
-4 - -2 # => -2
4 - 2.0 # => 2.0
4 - Rational(2, 1) # => (2/1)
4 - Complex(2, 0) # => (2+0i)
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# File 'numeric.c', line 4091 VALUE rb_int_minus(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_minus(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_minus(x, y); } return rb_num_coerce_bin(x, y, '-'); } |
#/(numeric) ⇒ Object
Performs division; for integer numeric
, truncates the result to an integer:
4 / 3 # => 1
4 / -3 # => -2
-4 / 3 # => -2
-4 / -3 # => 1
For other +numeric+, returns non-integer result:
4 / 3.0 # => 1.3333333333333333
4 / Rational(3, 1) # => (4/3)
4 / Complex(3, 0) # => ((4/3)+0i)
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# File 'numeric.c', line 4283 VALUE rb_int_div(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_div(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_div(x, y); } return Qnil; } |
#<(other) ⇒ Boolean
Returns true
if the value of self
is less than that of other
:
1 < 0 # => false
1 < 1 # => false
1 < 2 # => true
1 < 0.5 # => false
1 < Rational(1, 2) # => false
Raises an exception if the comparison cannot be made.
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# File 'numeric.c', line 4898 static VALUE int_lt(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_lt(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_lt(x, y); } return Qnil; } |
#<<(count) ⇒ Integer
Returns self
with bits shifted count
positions to the left, or to the right if count
is negative:
n = 0b11110000
"%08b" % (n << 1) # => "111100000"
"%08b" % (n << 3) # => "11110000000"
"%08b" % (n << -1) # => "01111000"
"%08b" % (n << -3) # => "00011110"
Related: Integer#>>.
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# File 'numeric.c', line 5173 VALUE rb_int_lshift(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return rb_fix_lshift(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_lshift(x, y); } return Qnil; } |
#<=(real) ⇒ Boolean
Returns true
if the value of self
is less than or equal to
that of +other+:
1 <= 0 # => false
1 <= 1 # => true
1 <= 2 # => true
1 <= 0.5 # => false
1 <= Rational(1, 2) # => false
Raises an exception if the comparison cannot be made.
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# File 'numeric.c', line 4945 static VALUE int_le(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_le(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_le(x, y); } return Qnil; } |
#<=>(other) ⇒ -1, ...
Returns:
-
-1, if
self
is less thanother
. -
0, if
self
is equal toother
. -
1, if
self
is greater thenother
. -
nil
, ifself
andother
are incomparable.
Examples:
1 <=> 2 # => -1
1 <=> 1 # => 0
1 <=> 0 # => 1
1 <=> 'foo' # => nil
1 <=> 1.0 # => 0
1 <=> Rational(1, 1) # => 0
1 <=> Complex(1, 0) # => 0
This method is the basis for comparisons in module Comparable.
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# File 'numeric.c', line 4759 VALUE rb_int_cmp(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_cmp(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_cmp(x, y); } else { rb_raise(rb_eNotImpError, "need to define '<=>' in %s", rb_obj_classname(x)); } } |
#==(other) ⇒ Boolean
Returns true
if self
is numerically equal to other
; false
otherwise.
1 == 2 #=> false
1 == 1.0 #=> true
Related: Integer#eql? (requires other
to be an Integer).
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# File 'numeric.c', line 4697 VALUE rb_int_equal(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_equal(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_eq(x, y); } return Qnil; } |
#==(other) ⇒ Boolean
Returns true
if self
is numerically equal to other
; false
otherwise.
1 == 2 #=> false
1 == 1.0 #=> true
Related: Integer#eql? (requires other
to be an Integer).
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# File 'numeric.c', line 4697 VALUE rb_int_equal(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_equal(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_eq(x, y); } return Qnil; } |
#>(other) ⇒ Boolean
Returns true
if the value of self
is greater than that of other
:
1 > 0 # => true
1 > 1 # => false
1 > 2 # => false
1 > 0.5 # => true
1 > Rational(1, 2) # => true
Raises an exception if the comparison cannot be made.
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# File 'numeric.c', line 4806 VALUE rb_int_gt(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_gt(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_gt(x, y); } return Qnil; } |
#>=(real) ⇒ Boolean
Returns true
if the value of self
is greater than or equal to that of other
:
1 >= 0 # => true
1 >= 1 # => true
1 >= 2 # => false
1 >= 0.5 # => true
1 >= Rational(1, 2) # => true
Raises an exception if the comparison cannot be made.
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# File 'numeric.c', line 4853 VALUE rb_int_ge(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_ge(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_ge(x, y); } return Qnil; } |
#>>(count) ⇒ Integer
Returns self
with bits shifted count
positions to the right, or to the left if count
is negative:
n = 0b11110000
"%08b" % (n >> 1) # => "01111000"
"%08b" % (n >> 3) # => "00011110"
"%08b" % (n >> -1) # => "111100000"
"%08b" % (n >> -3) # => "11110000000"
Related: Integer#<<.
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# File 'numeric.c', line 5229 VALUE rb_int_rshift(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return rb_fix_rshift(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_rshift(x, y); } return Qnil; } |
#[](offset) ⇒ 0, 1 #[](offset, size) ⇒ Integer #[](range) ⇒ Integer
Returns a slice of bits from self
.
With argument offset
, returns the bit at the given offset, where offset 0 refers to the least significant bit:
n = 0b10 # => 2
n[0] # => 0
n[1] # => 1
n[2] # => 0
n[3] # => 0
In principle, n[i]
is equivalent to (n >> i) & 1
. Thus, negative index always returns zero:
255[-1] # => 0
With arguments offset
and size
, returns size
bits from self
, beginning at offset
and including bits of greater significance:
n = 0b111000 # => 56
"%010b" % n[0, 10] # => "0000111000"
"%010b" % n[4, 10] # => "0000000011"
With argument range
, returns range.size
bits from self
, beginning at range.begin
and including bits of greater significance:
n = 0b111000 # => 56
"%010b" % n[0..9] # => "0000111000"
"%010b" % n[4..9] # => "0000000011"
Raises an exception if the slice cannot be constructed.
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# File 'numeric.c', line 5390 static VALUE int_aref(int const argc, VALUE * const argv, VALUE const num) { rb_check_arity(argc, 1, 2); if (argc == 2) { return int_aref2(num, argv[0], argv[1]); } return int_aref1(num, argv[0]); return Qnil; } |
#^(other) ⇒ Integer
Bitwise EXCLUSIVE OR; each bit in the result is 1 if the corresponding bits in self
and other
are different, 0 otherwise:
"%04b" % (0b0101 ^ 0b0110) # => "0011"
Raises an exception if other
is not an Integer.
Related: Integer#& (bitwise AND), Integer#| (bitwise OR).
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# File 'numeric.c', line 5118 static VALUE int_xor(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_xor(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_xor(x, y); } return Qnil; } |
#allbits?(mask) ⇒ Boolean
Returns true
if all bits that are set (=1) in mask
are also set in self
; returns false
otherwise.
Example values:
0b1010101 self
0b1010100 mask
0b1010100 self & mask
true self.allbits?(mask)
0b1010100 self
0b1010101 mask
0b1010100 self & mask
false self.allbits?(mask)
Related: Integer#anybits?, Integer#nobits?.
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# File 'numeric.c', line 3680 static VALUE int_allbits_p(VALUE num, VALUE mask) { mask = rb_to_int(mask); return rb_int_equal(rb_int_and(num, mask), mask); } |
#anybits?(mask) ⇒ Boolean
Returns true
if any bit that is set (=1) in mask
is also set in self
; returns false
otherwise.
Example values:
0b10000010 self
0b11111111 mask
0b10000010 self & mask
true self.anybits?(mask)
0b00000000 self
0b11111111 mask
0b00000000 self & mask
false self.anybits?(mask)
Related: Integer#allbits?, Integer#nobits?.
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# File 'numeric.c', line 3710 static VALUE int_anybits_p(VALUE num, VALUE mask) { mask = rb_to_int(mask); return RBOOL(!int_zero_p(rb_int_and(num, mask))); } |
#ceil(*args) ⇒ Object
:markup: markdown
call-seq:
ceil(ndigits = 0) -> integer
Returns an integer that is a “ceiling” value for ‘self`, as specified by the given `ndigits`, which must be an [integer-convertible object](implicit_conversion.rdoc@Integer-Convertible+Objects).
-
When ‘self` is zero, returns zero (regardless of the value of `ndigits`):
``` 0.ceil(2) # => 0 0.ceil(-2) # => 0 ```
-
When ‘self` is non-zero and `ndigits` is non-negative, returns `self`:
``` 555.ceil # => 555 555.ceil(50) # => 555 ```
-
When ‘self` is non-zero and `ndigits` is negative, returns a value based on a computed granularity:
- The granularity is `10 ** ndigits.abs`. - The returned value is the smallest multiple of the granularity that is greater than or equal to `self`. Examples with positive `self`: | ndigits | Granularity | 1234.ceil(ndigits) | |--------:|------------:|-------------------:| | -1 | 10 | 1240 | | -2 | 100 | 1300 | | -3 | 1000 | 2000 | | -4 | 10000 | 10000 | | -5 | 100000 | 100000 | Examples with negative `self`: | ndigits | Granularity | -1234.ceil(ndigits) | |--------:|------------:|--------------------:| | -1 | 10 | -1230 | | -2 | 100 | -1200 | | -3 | 1000 | -1000 | | -4 | 10000 | 0 | | -5 | 100000 | 0 |
Related: Integer#floor.
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# File 'numeric.c', line 5920 static VALUE int_ceil(int argc, VALUE* argv, VALUE num) { int ndigits; if (!rb_check_arity(argc, 0, 1)) return num; ndigits = NUM2INT(argv[0]); if (ndigits >= 0) { return num; } return rb_int_ceil(num, ndigits); } |
#chr ⇒ String #chr(encoding) ⇒ String
Returns a 1-character string containing the character represented by the value of self
, according to the given encoding
.
65.chr # => "A"
0.chr # => "\x00"
255.chr # => "\xFF"
string = 255.chr(Encoding::UTF_8)
string.encoding # => Encoding::UTF_8
Raises an exception if self
is negative.
Related: Integer#ord.
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# File 'numeric.c', line 3843 static VALUE int_chr(int argc, VALUE *argv, VALUE num) { char c; unsigned int i; rb_encoding *enc; if (rb_num_to_uint(num, &i) == 0) { } else if (FIXNUM_P(num)) { rb_raise(rb_eRangeError, "%ld out of char range", FIX2LONG(num)); } else { rb_raise(rb_eRangeError, "bignum out of char range"); } switch (argc) { case 0: if (0xff < i) { enc = rb_default_internal_encoding(); if (!enc) { rb_raise(rb_eRangeError, "%u out of char range", i); } goto decode; } c = (char)i; if (i < 0x80) { return rb_usascii_str_new(&c, 1); } else { return rb_str_new(&c, 1); } case 1: break; default: rb_error_arity(argc, 0, 1); } enc = rb_to_encoding(argv[0]); if (!enc) enc = rb_ascii8bit_encoding(); decode: return rb_enc_uint_chr(i, enc); } |
#coerce(numeric) ⇒ Array
Returns an array with both a numeric
and a int
represented as Integer objects or Float objects.
This is achieved by converting numeric
to an Integer or a Float.
A TypeError is raised if the numeric
is not an Integer or a Float type.
(0x3FFFFFFFFFFFFFFF+1).coerce(42) #=> [42, 4611686018427387904]
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# File 'bignum.c', line 6784 static VALUE rb_int_coerce(VALUE x, VALUE y) { if (RB_INTEGER_TYPE_P(y)) { return rb_assoc_new(y, x); } else { x = rb_Float(x); y = rb_Float(y); return rb_assoc_new(y, x); } } |
#digits(base = 10) ⇒ Object
Returns an array of integers representing the base
-radix digits of self
; the first element of the array represents the least significant digit:
12345.digits # => [5, 4, 3, 2, 1]
12345.digits(7) # => [4, 6, 6, 0, 5]
12345.digits(100) # => [45, 23, 1]
Raises an exception if self
is negative or base
is less than 2.
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# File 'numeric.c', line 5591 static VALUE rb_int_digits(int argc, VALUE *argv, VALUE num) { VALUE base_value; long base; if (rb_num_negative_p(num)) rb_raise(rb_eMathDomainError, "out of domain"); if (rb_check_arity(argc, 0, 1)) { base_value = rb_to_int(argv[0]); if (!RB_INTEGER_TYPE_P(base_value)) rb_raise(rb_eTypeError, "wrong argument type %s (expected Integer)", rb_obj_classname(argv[0])); if (RB_BIGNUM_TYPE_P(base_value)) return rb_int_digits_bigbase(num, base_value); base = FIX2LONG(base_value); if (base < 0) rb_raise(rb_eArgError, "negative radix"); else if (base < 2) rb_raise(rb_eArgError, "invalid radix %ld", base); } else base = 10; if (FIXNUM_P(num)) return rb_fix_digits(num, base); else if (RB_BIGNUM_TYPE_P(num)) return rb_int_digits_bigbase(num, LONG2FIX(base)); return Qnil; } |
#div(numeric) ⇒ Integer
Performs integer division; returns the integer result of dividing self
by numeric
:
4.div(3) # => 1
4.div(-3) # => -2
-4.div(3) # => -2
-4.div(-3) # => 1
4.div(3.0) # => 1
4.div(Rational(3, 1)) # => 1
Raises an exception if numeric
does not have method div
.
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# File 'numeric.c', line 4319 VALUE rb_int_idiv(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_idiv(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_idiv(x, y); } return num_div(x, y); } |
#divmod(other) ⇒ Array
Returns a 2-element array [q, r]
, where
q = (self/other).floor # Quotient
r = self % other # Remainder
Examples:
11.divmod(4) # => [2, 3]
11.divmod(-4) # => [-3, -1]
-11.divmod(4) # => [-3, 1]
-11.divmod(-4) # => [2, -3]
12.divmod(4) # => [3, 0]
12.divmod(-4) # => [-3, 0]
-12.divmod(4) # => [-3, 0]
-12.divmod(-4) # => [3, 0]
13.divmod(4.0) # => [3, 1.0]
13.divmod(Rational(4, 1)) # => [3, (1/1)]
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# File 'numeric.c', line 4489 VALUE rb_int_divmod(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_divmod(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_divmod(x, y); } return Qnil; } |
#downto(limit) {|i| ... } ⇒ self #downto(limit) ⇒ Object
Calls the given block with each integer value from self
down to limit
; returns self
:
a = []
10.downto(5) {|i| a << i } # => 10
a # => [10, 9, 8, 7, 6, 5]
a = []
0.downto(-5) {|i| a << i } # => 0
a # => [0, -1, -2, -3, -4, -5]
4.downto(5) {|i| fail 'Cannot happen' } # => 4
With no block given, returns an Enumerator.
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# File 'numeric.c', line 5701 static VALUE int_downto(VALUE from, VALUE to) { RETURN_SIZED_ENUMERATOR(from, 1, &to, int_downto_size); if (FIXNUM_P(from) && FIXNUM_P(to)) { long i, end; end = FIX2LONG(to); for (i=FIX2LONG(from); i >= end; i--) { rb_yield(LONG2FIX(i)); } } else { VALUE i = from, c; while (!(c = rb_funcall(i, '<', 1, to))) { rb_yield(i); i = rb_funcall(i, '-', 1, INT2FIX(1)); } if (NIL_P(c)) rb_cmperr(i, to); } return from; } |
#fdiv(numeric) ⇒ Float
Returns the Float result of dividing self
by numeric
:
4.fdiv(2) # => 2.0
4.fdiv(-2) # => -2.0
-4.fdiv(2) # => -2.0
4.fdiv(2.0) # => 2.0
4.fdiv(Rational(3, 4)) # => 5.333333333333333
Raises an exception if numeric
cannot be converted to a Float.
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# File 'numeric.c', line 4218 VALUE rb_int_fdiv(VALUE x, VALUE y) { if (RB_INTEGER_TYPE_P(x)) { return DBL2NUM(rb_int_fdiv_double(x, y)); } return Qnil; } |
#floor(*args) ⇒ Object
:markup: markdown
call-seq:
floor(ndigits = 0) -> integer
Returns an integer that is a “floor” value for ‘self`, as specified by the given `ndigits`, which must be an [integer-convertible object](implicit_conversion.rdoc@Integer-Convertible+Objects).
-
When ‘self` is zero, returns zero (regardless of the value of `ndigits`):
``` 0.floor(2) # => 0 0.floor(-2) # => 0 ```
-
When ‘self` is non-zero and `ndigits` is non-negative, returns `self`:
``` 555.floor # => 555 555.floor(50) # => 555 ```
-
When ‘self` is non-zero and `ndigits` is negative, returns a value based on a computed granularity:
- The granularity is `10 ** ndigits.abs`. - The returned value is the largest multiple of the granularity that is less than or equal to `self`. Examples with positive `self`: | ndigits | Granularity | 1234.floor(ndigits) | |--------:|------------:|--------------------:| | -1 | 10 | 1230 | | -2 | 100 | 1200 | | -3 | 1000 | 1000 | | -4 | 10000 | 0 | | -5 | 100000 | 0 | Examples with negative `self`: | ndigits | Granularity | -1234.floor(ndigits) | |--------:|------------:|---------------------:| | -1 | 10 | -1240 | | -2 | 100 | -1300 | | -3 | 1000 | -2000 | | -4 | 10000 | -10000 | | -5 | 100000 | -100000 |
Related: Integer#ceil.
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# File 'numeric.c', line 5852 static VALUE int_floor(int argc, VALUE* argv, VALUE num) { int ndigits; if (!rb_check_arity(argc, 0, 1)) return num; ndigits = NUM2INT(argv[0]); if (ndigits >= 0) { return num; } return rb_int_floor(num, ndigits); } |
#gcd(other_int) ⇒ Integer
Returns the greatest common divisor of the two integers. The result is always positive. 0.gcd(x) and x.gcd(0) return x.abs.
36.gcd(60) #=> 12
2.gcd(2) #=> 2
3.gcd(-7) #=> 1
((1<<31)-1).gcd((1<<61)-1) #=> 1
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# File 'rational.c', line 1914 VALUE rb_gcd(VALUE self, VALUE other) { other = nurat_int_value(other); return f_gcd(self, other); } |
#gcdlcm(other_int) ⇒ Array
Returns an array with the greatest common divisor and the least common multiple of the two integers, [gcd, lcm].
36.gcdlcm(60) #=> [12, 180]
2.gcdlcm(2) #=> [2, 2]
3.gcdlcm(-7) #=> [1, 21]
((1<<31)-1).gcdlcm((1<<61)-1) #=> [1, 4951760154835678088235319297]
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# File 'rational.c', line 1952 VALUE rb_gcdlcm(VALUE self, VALUE other) { other = nurat_int_value(other); return rb_assoc_new(f_gcd(self, other), f_lcm(self, other)); } |
#lcm(other_int) ⇒ Integer
Returns the least common multiple of the two integers. The result is always positive. 0.lcm(x) and x.lcm(0) return zero.
36.lcm(60) #=> 180
2.lcm(2) #=> 2
3.lcm(-7) #=> 21
((1<<31)-1).lcm((1<<61)-1) #=> 4951760154835678088235319297
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# File 'rational.c', line 1933 VALUE rb_lcm(VALUE self, VALUE other) { other = nurat_int_value(other); return f_lcm(self, other); } |
#%(other) ⇒ Object
Returns self
modulo other
as a real number.
For integer n
and real number r
, these expressions are equivalent:
n % r
n-r*(n/r).floor
n.divmod(r)[1]
See Numeric#divmod.
Examples:
10 % 2 # => 0
10 % 3 # => 1
10 % 4 # => 2
10 % -2 # => 0
10 % -3 # => -2
10 % -4 # => -2
10 % 3.0 # => 1.0
10 % Rational(3, 1) # => (1/1)
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# File 'numeric.c', line 4378 VALUE rb_int_modulo(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_mod(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_modulo(x, y); } return num_modulo(x, y); } |
#next ⇒ Object
#nobits?(mask) ⇒ Boolean
Returns true
if no bit that is set (=1) in mask
is also set in self
; returns false
otherwise.
Example values:
0b11110000 self
0b00001111 mask
0b00000000 self & mask
true self.nobits?(mask)
0b00000001 self
0b11111111 mask
0b00000001 self & mask
false self.nobits?(mask)
Related: Integer#allbits?, Integer#anybits?.
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# File 'numeric.c', line 3740 static VALUE int_nobits_p(VALUE num, VALUE mask) { mask = rb_to_int(mask); return RBOOL(int_zero_p(rb_int_and(num, mask))); } |
#pow(numeric) ⇒ Numeric #pow(integer, integer) ⇒ Integer
Returns (modular) exponentiation as:
a.pow(b) #=> same as a**b
a.pow(b, m) #=> same as (a**b) % m, but avoids huge temporary values
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# File 'bignum.c', line 7083 VALUE rb_int_powm(int const argc, VALUE * const argv, VALUE const num) { rb_check_arity(argc, 1, 2); if (argc == 1) { return rb_int_pow(num, argv[0]); } else { VALUE const a = num; VALUE const b = argv[0]; VALUE m = argv[1]; int nega_flg = 0; if ( ! RB_INTEGER_TYPE_P(b)) { rb_raise(rb_eTypeError, "Integer#pow() 2nd argument not allowed unless a 1st argument is integer"); } if (rb_int_negative_p(b)) { rb_raise(rb_eRangeError, "Integer#pow() 1st argument cannot be negative when 2nd argument specified"); } if (!RB_INTEGER_TYPE_P(m)) { rb_raise(rb_eTypeError, "Integer#pow() 2nd argument not allowed unless all arguments are integers"); } if (rb_int_negative_p(m)) { m = rb_int_uminus(m); nega_flg = 1; } if (FIXNUM_P(m)) { long const half_val = (long)HALF_LONG_MSB; long const mm = FIX2LONG(m); if (!mm) rb_num_zerodiv(); if (mm == 1) return INT2FIX(0); if (mm <= half_val) { return int_pow_tmp1(rb_int_modulo(a, m), b, mm, nega_flg); } else { return int_pow_tmp2(rb_int_modulo(a, m), b, mm, nega_flg); } } else { if (rb_bigzero_p(m)) rb_num_zerodiv(); if (bignorm(m) == INT2FIX(1)) return INT2FIX(0); return int_pow_tmp3(rb_int_modulo(a, m), b, m, nega_flg); } } UNREACHABLE_RETURN(Qnil); } |
#pred ⇒ Object
#rationalize([eps]) ⇒ Object
Returns the value as a rational. The optional argument eps
is always ignored.
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# File 'rational.c', line 2165 static VALUE integer_rationalize(int argc, VALUE *argv, VALUE self) { rb_check_arity(argc, 0, 1); return integer_to_r(self); } |
#remainder(other) ⇒ Object
Returns the remainder after dividing self
by other
.
Examples:
11.remainder(4) # => 3
11.remainder(-4) # => 3
-11.remainder(4) # => -3
-11.remainder(-4) # => -3
12.remainder(4) # => 0
12.remainder(-4) # => 0
-12.remainder(4) # => 0
-12.remainder(-4) # => 0
13.remainder(4.0) # => 1.0
13.remainder(Rational(4, 1)) # => (1/1)
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# File 'numeric.c', line 4413 static VALUE int_remainder(VALUE x, VALUE y) { if (FIXNUM_P(x)) { if (FIXNUM_P(y)) { VALUE z = fix_mod(x, y); RUBY_ASSERT(FIXNUM_P(z)); if (z != INT2FIX(0) && (SIGNED_VALUE)(x ^ y) < 0) z = fix_minus(z, y); return z; } else if (!RB_BIGNUM_TYPE_P(y)) { return num_remainder(x, y); } x = rb_int2big(FIX2LONG(x)); } else if (!RB_BIGNUM_TYPE_P(x)) { return Qnil; } return rb_big_remainder(x, y); } |
#round(ndigits = 0, half: :up) ⇒ Integer
Returns self
rounded to the nearest value with a precision of ndigits
decimal digits.
When ndigits
is negative, the returned value has at least ndigits.abs
trailing zeros:
555.round(-1) # => 560
555.round(-2) # => 600
555.round(-3) # => 1000
-555.round(-2) # => -600
555.round(-4) # => 0
Returns self
when ndigits
is zero or positive.
555.round # => 555
555.round(1) # => 555
555.round(50) # => 555
If keyword argument half
is given, and self
is equidistant from the two candidate values, the rounding is according to the given half
value:
-
:up
ornil
: round away from zero:25.round(-1, half: :up) # => 30 (-25).round(-1, half: :up) # => -30
-
:down
: round toward zero:25.round(-1, half: :down) # => 20 (-25).round(-1, half: :down) # => -20
-
:even
: round toward the candidate whose last nonzero digit is even:25.round(-1, half: :even) # => 20 15.round(-1, half: :even) # => 20 (-25).round(-1, half: :even) # => -20
Raises and exception if the value for half
is invalid.
Related: Integer#truncate.
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# File 'numeric.c', line 5780 static VALUE int_round(int argc, VALUE* argv, VALUE num) { int ndigits; int mode; VALUE nd, opt; if (!rb_scan_args(argc, argv, "01:", &nd, &opt)) return num; ndigits = NUM2INT(nd); mode = rb_num_get_rounding_option(opt); if (ndigits >= 0) { return num; } return rb_int_round(num, ndigits, mode); } |
#succ ⇒ Object
#to_f ⇒ Float
Converts self
to a Float:
1.to_f # => 1.0
-1.to_f # => -1.0
If the value of self
does not fit in a Float, the result is infinity:
(10**400).to_f # => Infinity
(-10**400).to_f # => -Infinity
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# File 'numeric.c', line 5419 static VALUE int_to_f(VALUE num) { double val; if (FIXNUM_P(num)) { val = (double)FIX2LONG(num); } else if (RB_BIGNUM_TYPE_P(num)) { val = rb_big2dbl(num); } else { rb_raise(rb_eNotImpError, "Unknown subclass for to_f: %s", rb_obj_classname(num)); } return DBL2NUM(val); } |
#to_r ⇒ Object
Returns the value as a rational.
1.to_r #=> (1/1)
(1<<64).to_r #=> (18446744073709551616/1)
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# File 'rational.c', line 2152 static VALUE integer_to_r(VALUE self) { return rb_rational_new1(self); } |
#to_s(base = 10) ⇒ String Also known as: inspect
Returns a string containing the place-value representation of self
in radix base
(in 2..36).
12345.to_s # => "12345"
12345.to_s(2) # => "11000000111001"
12345.to_s(8) # => "30071"
12345.to_s(10) # => "12345"
12345.to_s(16) # => "3039"
12345.to_s(36) # => "9ix"
78546939656932.to_s(36) # => "rubyrules"
Raises an exception if base
is out of range.
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# File 'numeric.c', line 3980 VALUE rb_int_to_s(int argc, VALUE *argv, VALUE x) { int base; if (rb_check_arity(argc, 0, 1)) base = NUM2INT(argv[0]); else base = 10; return rb_int2str(x, base); } |
#truncate(ndigits = 0) ⇒ Integer
Returns self
truncated (toward zero) to a precision of ndigits
decimal digits.
When ndigits
is negative, the returned value has at least ndigits.abs
trailing zeros:
555.truncate(-1) # => 550
555.truncate(-2) # => 500
-555.truncate(-2) # => -500
Returns self
when ndigits
is zero or positive.
555.truncate # => 555
555.truncate(50) # => 555
Related: Integer#round.
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# File 'numeric.c', line 5956 static VALUE int_truncate(int argc, VALUE* argv, VALUE num) { int ndigits; if (!rb_check_arity(argc, 0, 1)) return num; ndigits = NUM2INT(argv[0]); if (ndigits >= 0) { return num; } return rb_int_truncate(num, ndigits); } |
#upto(limit) {|i| ... } ⇒ self #upto(limit) ⇒ Object
Calls the given block with each integer value from self
up to limit
; returns self
:
a = []
5.upto(10) {|i| a << i } # => 5
a # => [5, 6, 7, 8, 9, 10]
a = []
-5.upto(0) {|i| a << i } # => -5
a # => [-5, -4, -3, -2, -1, 0]
5.upto(4) {|i| fail 'Cannot happen' } # => 5
With no block given, returns an Enumerator.
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# File 'numeric.c', line 5651 static VALUE int_upto(VALUE from, VALUE to) { RETURN_SIZED_ENUMERATOR(from, 1, &to, int_upto_size); if (FIXNUM_P(from) && FIXNUM_P(to)) { long i, end; end = FIX2LONG(to); for (i = FIX2LONG(from); i <= end; i++) { rb_yield(LONG2FIX(i)); } } else { VALUE i = from, c; while (!(c = rb_funcall(i, '>', 1, to))) { rb_yield(i); i = rb_funcall(i, '+', 1, INT2FIX(1)); } ensure_cmp(c, i, to); } return from; } |
#|(other) ⇒ Integer
Bitwise OR; each bit in the result is 1 if either corresponding bit in self
or other
is 1, 0 otherwise:
"%04b" % (0b0101 | 0b0110) # => "0111"
Raises an exception if other
is not an Integer.
Related: Integer#& (bitwise AND), Integer#^ (bitwise EXCLUSIVE OR).
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# File 'numeric.c', line 5076 static VALUE int_or(VALUE x, VALUE y) { if (FIXNUM_P(x)) { return fix_or(x, y); } else if (RB_BIGNUM_TYPE_P(x)) { return rb_big_or(x, y); } return Qnil; } |