An Integer object represents an integer value.
You can create an Integer object explicitly with:
An integer literal.
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.
Whatâs Here¶ ↑First, whatâs elsewhere. Class Integer:
Inherits from class Numeric and class Object.
Includes module Comparable.
Here, class Integer provides methods for:
Querying¶ ↑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.
<
: 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.
::sqrt
: Returns the integer square root of the given value.
::try_convert
: Returns the given value converted to an Integer.
&
: 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_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.
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 (0..self-1)
.
upto
: Calls the given block with each integer value from self
up to the given value.
The version of loaded GMP.
static VALUE rb_int_s_isqrt(VALUE self, VALUE num) { unsigned long n, sq; num = rb_to_int(num); if (FIXNUM_P(num)) { if (FIXNUM_NEGATIVE_P(num)) { domain_error("isqrt"); } n = FIX2ULONG(num); sq = rb_ulong_isqrt(n); return LONG2FIX(sq); } else { size_t biglen; if (RBIGNUM_NEGATIVE_P(num)) { domain_error("isqrt"); } biglen = BIGNUM_LEN(num); if (biglen == 0) return INT2FIX(0); #if SIZEOF_BDIGIT <= SIZEOF_LONG /* short-circuit */ if (biglen == 1) { n = BIGNUM_DIGITS(num)[0]; sq = rb_ulong_isqrt(n); return ULONG2NUM(sq); } #endif return rb_big_isqrt(num); } }
Returns the integer square root of the non-negative integer n
, which is the largest non-negative integer less than or equal to the square root of numeric
.
Integer.sqrt(0) Integer.sqrt(1) Integer.sqrt(24) Integer.sqrt(25) Integer.sqrt(10**400)
If numeric
is not an Integer, it is converted to an Integer:
Integer.sqrt(Complex(4, 0)) Integer.sqrt(Rational(4, 1)) Integer.sqrt(4.0) Integer.sqrt(3.14159)
This method is equivalent to Math.sqrt(numeric).floor
, except that the result of the latter code may differ from the true value due to the limited precision of floating point arithmetic.
Integer.sqrt(10**46) Math.sqrt(10**46).floor
Raises an exception if numeric
is negative.
static VALUE int_s_try_convert(VALUE self, VALUE num) { return rb_check_integer_type(num); }
If object
is an Integer object, returns object
.
Integer.try_convert(1)
Otherwise if object
responds to :to_int
, calls object.to_int
and returns the result.
Integer.try_convert(1.25)
Returns nil
if object
does not respond to :to_int
Integer.try_convert([])
Raises an exception unless object.to_int
returns an Integer object.
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); }
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 10 % 3 10 % 4 10 % -2 10 % -3 10 % -4 10 % 3.0 10 % Rational(3, 1)Source
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; }
Bitwise AND; each bit in the result is 1 if both corresponding bits in self
and other
are 1, 0 otherwise:
"%04b" % (0b0101 & 0b0110)
Raises an exception if other
is not an Integer.
Related: Integer#|
(bitwise OR), Integer#^
(bitwise EXCLUSIVE OR).
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, '*'); }
Performs multiplication:
4 * 2 4 * -2 -4 * 2 4 * 2.0 4 * Rational(1, 3) 4 * Complex(2, 0)Source
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; }
Raises self
to the power of numeric
:
2 ** 3 2 ** -3 -2 ** 3 -2 ** -3 2 ** 3.3 2 ** Rational(3, 1) 2 ** Complex(3, 0)Source
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, '+'); }
Performs addition:
2 + 2 -2 + 2 -2 + -2 2 + 2.0 2 + Rational(2, 1) 2 + Complex(2, 0)Source
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, '-'); }
Performs subtraction:
4 - 2 -4 - 2 -4 - -2 4 - 2.0 4 - Rational(2, 1) 4 - Complex(2, 0)Source
def -@ Primitive.attr! :leaf Primitive.cexpr! 'rb_int_uminus(self)' end
Returns self
, negated.
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; }
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)Source
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; }
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.Source
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; }
Returns self
with bits shifted count
positions to the left, or to the right if count
is negative:
n = 0b11110000 "%08b" % (n << 1) "%08b" % (n << 3) "%08b" % (n << -1) "%08b" % (n << -3)
Related: Integer#>>
.
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; }
Returns true
if the value of self
is less than or equal to that of other
:
1 <= 0 1 <= 1 1 <= 2 1 <= 0.5 1 <= Rational(1, 2)
Raises an exception if the comparison cannot be made.
SourceVALUE 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)); } }
Returns:
-1, if self
is less than other
.
0, if self
is equal to other
.
1, if self
is greater then other
.
nil
, if self
and other
are incomparable.
Examples:
1 <=> 2 1 <=> 1 1 <=> 0 1 <=> 'foo' 1 <=> 1.0 1 <=> Rational(1, 1) 1 <=> Complex(1, 0)
This method is the basis for comparisons in module Comparable
.
Returns true
if self
is numerically equal to other
; false
otherwise.
1 == 2 1 == 1.0
Related: Integer#eql?
(requires other
to be an Integer).
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; }
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.Source
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; }
Returns true
if the value of self
is greater than or equal to that of other
:
1 >= 0 1 >= 1 1 >= 2 1 >= 0.5 1 >= Rational(1, 2)
Raises an exception if the comparison cannot be made.
SourceVALUE 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; }
Returns self
with bits shifted count
positions to the right, or to the left if count
is negative:
n = 0b11110000 "%08b" % (n >> 1) "%08b" % (n >> 3) "%08b" % (n >> -1) "%08b" % (n >> -3)
Related: Integer#<<
.
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; }
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 n[0] n[1] n[2] n[3]
In principle, n[i]
is equivalent to (n >> i) & 1
. Thus, negative index always returns zero:
255[-1]
With arguments offset
and size
, returns size
bits from self
, beginning at offset
and including bits of greater significance:
n = 0b111000 "%010b" % n[0, 10] "%010b" % n[4, 10]
With argument range
, returns range.size
bits from self
, beginning at range.begin
and including bits of greater significance:
n = 0b111000 "%010b" % n[0..9] "%010b" % n[4..9]
Raises an exception if the slice cannot be constructed.
Sourcestatic 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; }
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)
Raises an exception if other
is not an Integer.
Related: Integer#&
(bitwise AND), Integer#|
(bitwise OR).
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; }
Bitwise OR; each bit in the result is 1 if either corresponding bit in self
or other
is 1, 0 otherwise:
"%04b" % (0b0101 | 0b0110)
Raises an exception if other
is not an Integer.
Related: Integer#&
(bitwise AND), Integer#^
(bitwise EXCLUSIVE OR).
def ~ Primitive.attr! :leaf Primitive.cexpr! 'rb_int_comp(self)' end
Oneâs complement: returns the value of self
with each bit inverted.
Because an integer value is conceptually of infinite length, the result acts as if it had an infinite number of one bits to the left. In hex representations, this is displayed as two periods to the left of the digits:
sprintf("%X", ~0x1122334455)Source
def abs Primitive.attr! :leaf Primitive.cexpr! 'rb_int_abs(self)' end
Returns the absolute value of self
.
(-12345).abs -12345.abs 12345.absSource
static VALUE int_allbits_p(VALUE num, VALUE mask) { mask = rb_to_int(mask); return rb_int_equal(rb_int_and(num, mask), mask); }
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?
.
static VALUE int_anybits_p(VALUE num, VALUE mask) { mask = rb_to_int(mask); return RBOOL(!int_zero_p(rb_int_and(num, mask))); }
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?
.
def bit_length Primitive.attr! :leaf Primitive.cexpr! 'rb_int_bit_length(self)' end
Returns the number of bits of the value of self
, which is the bit position of the highest-order bit that is different from the sign bit (where the least significant bit has bit position 1). If there is no such bit (zero or minus one), returns zero.
This method returns ceil(log2(self < 0 ? -self : self + 1))
>.
(-2**1000-1).bit_length (-2**1000).bit_length (-2**1000+1).bit_length (-2**12-1).bit_length (-2**12).bit_length (-2**12+1).bit_length -0x101.bit_length -0x100.bit_length -0xff.bit_length -2.bit_length -1.bit_length 0.bit_length 1.bit_length 0xff.bit_length 0x100.bit_length (2**12-1).bit_length (2**12).bit_length (2**12+1).bit_length (2**1000-1).bit_length (2**1000).bit_length (2**1000+1).bit_length
For Integer n, this method can be used to detect overflow in Array#pack
:
if n.bit_length < 32 [n].pack('l') else raise 'Overflow' endSource
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); }
Returns an integer that is a âceilingâ value for self
, as specified by the given ndigits
, which must be an integer-convertible object.
When self
is zero, returns zero (regardless of the value of ndigits
):
0.ceil(2) 0.ceil(-2)
When self
is non-zero and ndigits
is non-negative, returns self
:
555.ceil 555.ceil(50)
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
:
Examples with negative self
:
Related: Integer#floor
.
def ceildiv(other) -div(0 - other) end
Returns the result of division self
by numeric
. rounded up to the nearest integer.
3.ceildiv(3) 4.ceildiv(3) 4.ceildiv(-3) -4.ceildiv(3) -4.ceildiv(-3) 3.ceildiv(1.2)Source
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); }
Returns a 1-character string containing the character represented by the value of self
, according to the given encoding
.
65.chr 0.chr 255.chr string = 255.chr(Encoding::UTF_8) string.encoding
Raises an exception if self
is negative.
Related: Integer#ord
.
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); } }
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)Source
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; }
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 12345.digits(7) 12345.digits(100)
Raises an exception if self
is negative or base
is less than 2.
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); }
Performs integer division; returns the integer result of dividing self
by numeric
:
4.div(3) 4.div(-3) -4.div(3) -4.div(-3) 4.div(3.0) 4.div(Rational(3, 1))
Raises an exception if numeric
does not have method div
.
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; }
Returns a 2-element array [q, r]
, where
q = (self/other).floor r = self % other
Examples:
11.divmod(4) 11.divmod(-4) -11.divmod(4) -11.divmod(-4) 12.divmod(4) 12.divmod(-4) -12.divmod(4) -12.divmod(-4) 13.divmod(4.0) 13.divmod(Rational(4, 1))Source
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; }
Calls the given block with each integer value from self
down to limit
; returns self
:
a = [] 10.downto(5) {|i| a << i } a a = [] 0.downto(-5) {|i| a << i } a 4.downto(5) {|i| fail 'Cannot happen' }
With no block given, returns an Enumerator
.
def even? Primitive.attr! :leaf Primitive.cexpr! 'rb_int_even_p(self)' end
Returns true
if self
is an even number, false
otherwise.
VALUE rb_int_fdiv(VALUE x, VALUE y) { if (RB_INTEGER_TYPE_P(x)) { return DBL2NUM(rb_int_fdiv_double(x, y)); } return Qnil; }
Returns the Float
result of dividing self
by numeric
:
4.fdiv(2) 4.fdiv(-2) -4.fdiv(2) 4.fdiv(2.0) 4.fdiv(Rational(3, 4))
Raises an exception if numeric
cannot be converted to a Float
.
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); }
Returns an integer that is a âfloorâ value for self
, as specified by the given ndigits
, which must be an integer-convertible object.
When self
is zero, returns zero (regardless of the value of ndigits
):
0.floor(2) 0.floor(-2)
When self
is non-zero and ndigits
is non-negative, returns self
:
555.floor 555.floor(50)
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
:
Examples with negative self
:
Related: Integer#ceil
.
VALUE rb_gcd(VALUE self, VALUE other) { other = nurat_int_value(other); return f_gcd(self, other); }
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) 2.gcd(2) 3.gcd(-7) ((1<<31)-1).gcd((1<<61)-1)Source
VALUE rb_gcdlcm(VALUE self, VALUE other) { other = nurat_int_value(other); return rb_assoc_new(f_gcd(self, other), f_lcm(self, other)); }
Returns an array with the greatest common divisor and the least common multiple of the two integers, [gcd, lcm].
36.gcdlcm(60) 2.gcdlcm(2) 3.gcdlcm(-7) ((1<<31)-1).gcdlcm((1<<61)-1)Source
Since self
is already an Integer, always returns true
.
VALUE rb_lcm(VALUE self, VALUE other) { other = nurat_int_value(other); return f_lcm(self, other); }
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) 2.lcm(2) 3.lcm(-7) ((1<<31)-1).lcm((1<<61)-1)Source
static VALUE int_nobits_p(VALUE num, VALUE mask) { mask = rb_to_int(mask); return RBOOL(int_zero_p(rb_int_and(num, mask))); }
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?
.
def odd? Primitive.attr! :leaf Primitive.cexpr! 'rb_int_odd_p(self)' end
Returns true
if self
is an odd number, false
otherwise.
Returns self
; intended for compatibility to character literals in Ruby 1.9.
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); }
Returns (modular) exponentiation as:
a.pow(b) a.pow(b, m)Source
static VALUE rb_int_pred(VALUE num) { if (FIXNUM_P(num)) { long i = FIX2LONG(num) - 1; return LONG2NUM(i); } if (RB_BIGNUM_TYPE_P(num)) { return rb_big_minus(num, INT2FIX(1)); } return num_funcall1(num, '-', INT2FIX(1)); }
Returns the predecessor of self
(equivalent to self - 1
):
1.pred -1.pred
Related: Integer#succ
(successor value).
static VALUE integer_rationalize(int argc, VALUE *argv, VALUE self) { rb_check_arity(argc, 0, 1); return integer_to_r(self); }
Returns the value as a rational. The optional argument eps
is always ignored.
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); }
Returns the remainder after dividing self
by other
.
Examples:
11.remainder(4) 11.remainder(-4) -11.remainder(4) -11.remainder(-4) 12.remainder(4) 12.remainder(-4) -12.remainder(4) -12.remainder(-4) 13.remainder(4.0) 13.remainder(Rational(4, 1))Source
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); }
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) 555.round(-2) 555.round(-3) -555.round(-2) 555.round(-4)
Returns self
when ndigits
is zero or positive.
555.round 555.round(1) 555.round(50)
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
or nil
: round away from zero:
25.round(-1, half: :up) (-25).round(-1, half: :up)
:down
: round toward zero:
25.round(-1, half: :down) (-25).round(-1, half: :down)
:even
: round toward the candidate whose last nonzero digit is even:
25.round(-1, half: :even) 15.round(-1, half: :even) (-25).round(-1, half: :even)
Raises and exception if the value for half
is invalid.
Related: Integer#truncate
.
def size Primitive.attr! :leaf Primitive.cexpr! 'rb_int_size(self)' end
Returns the number of bytes in the machine representation of self
; the value is system-dependent:
1.size -1.size 2147483647.size (256**10 - 1).size (256**20 - 1).size (256**40 - 1).sizeSource
VALUE rb_int_succ(VALUE num) { if (FIXNUM_P(num)) { long i = FIX2LONG(num) + 1; return LONG2NUM(i); } if (RB_BIGNUM_TYPE_P(num)) { return rb_big_plus(num, INT2FIX(1)); } return num_funcall1(num, '+', INT2FIX(1)); }
Returns the successor integer of self
(equivalent to self + 1
):
1.succ -1.succ
Related: Integer#pred
(predecessor value).
def times Primitive.attr! :inline_block unless defined?(yield) return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, int_dotimes_size)' end i = 0 while i < self yield i i = i.succ end self end
Calls the given block self
times with each integer in (0..self-1)
:
a = [] 5.times {|i| a.push(i) } a
With no block given, returns an Enumerator
.
def to_bn OpenSSL::BN::new(self) end
Casts an Integer
as an OpenSSL::BN
See âman bn` for more info.
Sourcestatic 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); }
Converts self
to a Float:
1.to_f -1.to_f
If the value of self
does not fit in a Float
, the result is infinity:
(10**400).to_f (-10**400).to_fSource
Returns self
(which is already an Integer).
Returns self
(which is already an Integer).
static VALUE integer_to_r(VALUE self) { return rb_rational_new1(self); }
Returns the value as a rational.
1.to_r (1<<64).to_rSource
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); }
Returns a string containing the place-value representation of self
in radix base
(in 2..36).
12345.to_s 12345.to_s(2) 12345.to_s(8) 12345.to_s(10) 12345.to_s(16) 12345.to_s(36) 78546939656932.to_s(36)
Raises an exception if base
is out of range.
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); }
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) 555.truncate(-2) -555.truncate(-2)
Returns self
when ndigits
is zero or positive.
555.truncate 555.truncate(50)
Related: Integer#round
.
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; }
Calls the given block with each integer value from self
up to limit
; returns self
:
a = [] 5.upto(10) {|i| a << i } a a = [] -5.upto(0) {|i| a << i } a 5.upto(4) {|i| fail 'Cannot happen' }
With no block given, returns an Enumerator
.
def zero? Primitive.attr! :leaf Primitive.cexpr! 'rb_int_zero_p(self)' end
Returns true
if self
has a zero value, false
otherwise.
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