123456789_123456789_123456789_123456789_123456789_

Class: Integer

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::Numeric
Instance Chain:
Inherits: Numeric
Defined in: numeric.c,
bignum.c,
integer.rb,
rational.c

Overview

Holds Integer values. You cannot add a singleton method to an Integer object, any attempt to do so will raise a ::TypeError.

Constant Summary

Class Method Summary

  • .sqrt(n) ⇒ Integer

    Returns the integer square root of the non-negative integer n, i.e. the largest non-negative integer less than or equal to the square root of n.

Instance Attribute Summary

::Numeric - Inherited

#finite?

Returns true if num is a finite number, otherwise returns false.

#infinite?

Returns nil, -1, or 1 depending on whether the value is finite, -Infinity, or +Infinity.

#integer?

Returns true if num is an Integer.

#negative?

Returns true if num is less than 0.

#nonzero?

Returns self if num is not zero, nil otherwise.

#positive?

Returns true if num is greater than 0.

#real

Returns self.

#real?

Returns true if num is a real number (i.e.

#zero?

Returns true if num has a zero value.

Instance Method Summary

::Numeric - Inherited

#%

x.modulo(y) means x-y*(x/y).floor.

#+@

Unary Plus—Returns the receiver.

#-@

Unary Minus—Returns the receiver, negated.

#<=>

Returns zero if number equals other, otherwise returns nil.

#abs

Returns the absolute value of num.

#abs2

Returns square of self.

#angle

Alias for Numeric#arg.

#arg

Returns 0 if the value is positive, pi otherwise.

#ceil

Returns the smallest number greater than or equal to num with a precision of ndigits decimal digits (default: 0).

#clone

Returns the receiver.

#coerce

If numeric is the same type as num, returns an array [numeric, num].

#conj

Returns self.

#conjugate

Alias for Numeric#conj.

#denominator

Returns the denominator (always positive).

#div

Uses #/ to perform division, then converts the result to an integer.

#divmod

Returns an array containing the quotient and modulus obtained by dividing num by numeric.

#dup

Returns the receiver.

#eql?

Returns true if num and numeric are the same type and have equal values.

#fdiv

Returns float division.

#floor

Returns the largest number less than or equal to num with a precision of ndigits decimal digits (default: 0).

#i

Returns the corresponding imaginary number.

#imag

Returns zero.

#imaginary

Alias for Numeric#imag.

#magnitude

Alias for Numeric#abs.

#modulo

Alias for Numeric#%.

#numerator

Returns the numerator.

#phase

Alias for Numeric#arg.

#polar

Returns an array; [num.abs, num.arg].

#quo

Returns the most exact division (rational for integers, float for floats).

#rect

Returns an array; [num, 0].

#rectangular

Alias for Numeric#rect.

#remainder

x.remainder(y) means x-y*(x/y).truncate.

#round

Returns num rounded to the nearest value with a precision of ndigits decimal digits (default: 0).

#step

Invokes the given block with the sequence of numbers starting at num, incremented by step (defaulted to 1) on each call.

#to_c

Returns the value as a complex.

#to_int

Invokes the child class's #to_i method to convert num to an integer.

#truncate

Returns num truncated (toward zero) to a precision of ndigits decimal digits (default: 0).

#singleton_method_added

Trap attempts to add methods to ::Numeric objects.

::Comparable - Included

#<

Compares two objects based on the receiver's #<=> method, returning true if it returns a value less than 0.

#<=

Compares two objects based on the receiver's #<=> method, returning true if it returns a value less than or equal to 0.

#==

Compares two objects based on the receiver's #<=> method, returning true if it returns 0.

#>

Compares two objects based on the receiver's #<=> method, returning true if it returns a value greater than 0.

#>=

Compares two objects based on the receiver's #<=> method, returning true if it returns a value greater than or equal to 0.

#between?

Returns false if obj #<=> min is less than zero or if obj #<=> max is greater than zero, true otherwise.

#clamp

In (min, max) form, returns min if obj #<=> min is less than zero, max if obj #<=> max is greater than zero, and obj otherwise.

Class Method Details

.sqrt(n) ⇒ Integer

Returns the integer square root of the non-negative integer n, i.e. the largest non-negative integer less than or equal to the square root of n.

Integer.sqrt(0)        #=> 0
Integer.sqrt(1)        #=> 1
Integer.sqrt(24)       #=> 4
Integer.sqrt(25)       #=> 5
Integer.sqrt(10**400)  #=> 10**200

Equivalent to Math.sqrt(n).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)     #=> 100000000000000000000000
Math.sqrt(10**46).floor  #=>  99999999999999991611392 (!)

If n is not an Integer, it is converted to an Integer first. If n is negative, a ::Math::DomainError is raised.

[ GitHub ]

  
# File 'numeric.c', line 5397

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);
    }
}

Instance Attribute Details

#even?Boolean (readonly)

Returns true if int is an even number.

[ GitHub ]

  
# File 'integer.rb', line 16

def even?
  Primitive.attr! 'inline'
  Primitive.cexpr! 'int_even_p(self)'
end

#integer?Boolean (readonly)

Since int is already an Integer, this always returns true.

[ GitHub ]

  
# File 'integer.rb', line 25

def integer?
  return true
end

#odd?Boolean (readonly)

Returns true if int is an odd number.

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# File 'integer.rb', line 38

def odd?
  Primitive.attr! 'inline'
  Primitive.cexpr! 'rb_int_odd_p(self)'
end

#zero?Boolean (readonly)

Returns true if int has a zero value.

[ GitHub ]

  
# File 'integer.rb', line 80

def zero?
  Primitive.attr! 'inline'
  Primitive.cexpr! 'int_zero_p(self)'
end

Instance Method Details

#%(other) ⇒ Numeric #modulo(other) ⇒ Numeric
Also known as: #modulo

Returns int modulo other.

See Numeric#divmod for more information.

[ GitHub ]

  
# File 'numeric.c', line 3856

VALUE
rb_int_modulo(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_mod(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_modulo(x, y);
    }
    return num_modulo(x, y);
}

#&(other_int) ⇒ Integer

Bitwise AND.

[ GitHub ]

  
# File 'numeric.c', line 4434

VALUE
rb_int_and(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_and(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_and(x, y);
    }
    return Qnil;
}

#*(numeric) ⇒ numeric_result

Performs multiplication: the class of the resulting object depends on the class of numeric.

[ GitHub ]

  
# File 'numeric.c', line 3669

VALUE
rb_int_mul(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_mul(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_mul(x, y);
    }
    return rb_num_coerce_bin(x, y, '*');
}

#**(numeric) ⇒ numeric_result

Raises int to the power of numeric, which may be negative or fractional. The result may be an Integer, a ::Float, a ::Rational, or a complex number.

2 ** 3        #=> 8
2 ** -1       #=> (1/2)
2 ** 0.5      #=> 1.4142135623730951
(-1) ** 0.5   #=> (0.0+1.0i)

123456789 ** 2     #=> 15241578750190521
123456789 ** 1.2   #=> 5126464716.0993185
123456789 ** -2    #=> (1/15241578750190521)
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# File 'numeric.c', line 4071

VALUE
rb_int_pow(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_pow(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_pow(x, y);
    }
    return Qnil;
}

#+(numeric) ⇒ numeric_result

Performs addition: the class of the resulting object depends on the class of numeric.

[ GitHub ]

  
# File 'numeric.c', line 3580

VALUE
rb_int_plus(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_plus(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_plus(x, y);
    }
    return rb_num_coerce_bin(x, y, '+');
}

#-(numeric) ⇒ numeric_result

Performs subtraction: the class of the resulting object depends on the class of numeric.

[ GitHub ]

  
# File 'numeric.c', line 3619

VALUE
rb_int_minus(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_minus(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_minus(x, y);
    }
    return rb_num_coerce_bin(x, y, '-');
}

#-Integer

Returns int, negated.

[ GitHub ]

  
# File 'numeric.c', line 3449

VALUE
rb_int_uminus(VALUE num)
{
    if (FIXNUM_P(num)) {
	return fix_uminus(num);
    }
    else if (RB_TYPE_P(num, T_BIGNUM)) {
	return rb_big_uminus(num);
    }
    return num_funcall0(num, idUMinus);
}

#/(numeric) ⇒ numeric_result

Performs division: the class of the resulting object depends on the class of numeric.

[ GitHub ]

  
# File 'numeric.c', line 3786

VALUE
rb_int_div(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_div(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_div(x, y);
    }
    return Qnil;
}

#<(real) ⇒ Boolean

Returns true if the value of int is less than that of real.

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# File 'numeric.c', line 4297

static VALUE
int_lt(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_lt(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_lt(x, y);
    }
    return Qnil;
}

#<<(count) ⇒ Integer

Returns int shifted left count positions, or right if count is negative.

[ GitHub ]

  
# File 'numeric.c', line 4550

VALUE
rb_int_lshift(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return rb_fix_lshift(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_lshift(x, y);
    }
    return Qnil;
}

#<=(real) ⇒ Boolean

Returns true if the value of int is less than or equal to that of real.

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# File 'numeric.c', line 4337

static VALUE
int_le(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_le(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_le(x, y);
    }
    return Qnil;
}

#<=>(numeric) ⇒ 1, ...

Comparison—Returns -1, 0, or +1 depending on whether int is less than, equal to, or greater than numeric.

This is the basis for the tests in the ::Comparable module.

nil is returned if the two values are incomparable.

[ GitHub ]

  
# File 'numeric.c', line 4179

VALUE
rb_int_cmp(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_cmp(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_cmp(x, y);
    }
    else {
	rb_raise(rb_eNotImpError, "need to define `<=>' in %s", rb_obj_classname(x));
    }
}

#==(other) ⇒ Boolean Also known as: #===

Returns true if int equals other numerically. Contrast this with Integer#eql?, which requires other to be an Integer.

1 == 2     #=> false
1 == 1.0   #=> true
[ GitHub ]

  
# File 'numeric.c', line 4130

VALUE
rb_int_equal(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_equal(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_eq(x, y);
    }
    return Qnil;
}

#==(other) ⇒ Boolean #===(other) ⇒ Boolean

Alias for #==.

#>(real) ⇒ Boolean

Returns true if the value of int is greater than that of real.

[ GitHub ]

  
# File 'numeric.c', line 4219

VALUE
rb_int_gt(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_gt(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_gt(x, y);
    }
    return Qnil;
}

#>=(real) ⇒ Boolean

Returns true if the value of int is greater than or equal to that of real.

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# File 'numeric.c', line 4259

VALUE
rb_int_ge(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_ge(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_ge(x, y);
    }
    return Qnil;
}

#>>(count) ⇒ Integer

Returns int shifted right count positions, or left if count is negative.

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# File 'numeric.c', line 4597

static VALUE
rb_int_rshift(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return rb_fix_rshift(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_rshift(x, y);
    }
    return Qnil;
}

#[](n) ⇒ 0, 1 #[](n, m) ⇒ Numeric #[](range) ⇒ Numeric

Bit Reference—Returns the nth bit in the binary representation of int, where int[0] is the least significant bit.

a = 0b11001100101010
30.downto(0) {|n| print a[n] }
#=> 0000000000000000011001100101010

a = 9**15
50.downto(0) {|n| print a[n] }
#=> 000101110110100000111000011110010100111100010111001

In principle, n[i] is equivalent to (n >> i) & 1. Thus, any negative index always returns zero:

p 255[-1] #=> 0

::Range operations n[i, len] and n[i..j] are naturally extended.

  • n[i, len] equals to (n >> i) & ((1 << len) - 1).

  • n[i..j] equals to (n >> i) & ((1 << (j - i + 1)) - 1).

  • n[i...j] equals to (n >> i) & ((1 << (j - i)) - 1).

  • n[i..] equals to (n >> i).

  • n[..j] is zero if n & ((1 << (j + 1)) - 1) is zero. Otherwise, raises an ::ArgumentError.

  • n[...j] is zero if n & ((1 << j) - 1) is zero. Otherwise, raises an ::ArgumentError.

Note that range operation may exhaust memory. For example, -1[0, 1000000000000] will raise ::NoMemoryError.

[ GitHub ]

  
# File 'numeric.c', line 4757

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_int) ⇒ Integer

Bitwise EXCLUSIVE OR.

[ GitHub ]

  
# File 'numeric.c', line 4504

static VALUE
int_xor(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_xor(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_xor(x, y);
    }
    return Qnil;
}

#abs

[ GitHub ]

  
# File 'integer.rb', line 2

def abs
  Primitive.attr! 'inline'
  Primitive.cexpr! 'rb_int_abs(self)'
end

#allbits?(mask) ⇒ Boolean

Returns true if all bits of int & {mask} are 1.

[ GitHub ]

  
# File 'numeric.c', line 3260

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 bits of int & {mask} are 1.

[ GitHub ]

  
# File 'numeric.c', line 3274

static VALUE
int_anybits_p(VALUE num, VALUE mask)
{
    mask = rb_to_int(mask);
    return int_zero_p(rb_int_and(num, mask)) ? Qfalse : Qtrue;
}

#bit_length

[ GitHub ]

  
# File 'integer.rb', line 7

def bit_length
  Primitive.attr! 'inline'
  Primitive.cexpr! 'rb_int_bit_length(self)'
end

#ceil([ndigits]) ⇒ Integer, Float

Returns the smallest number greater than or equal to int with a precision of ndigits decimal digits (default: 0).

When the precision is negative, the returned value is an integer with at least ndigits.abs trailing zeros.

Returns self when ndigits is zero or positive.

1.ceil           #=> 1
1.ceil(2)        #=> 1
18.ceil(-1)      #=> 20
(-18).ceil(-1)   #=> -10
[ GitHub ]

  
# File 'numeric.c', line 5283

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([encoding]) ⇒ String

Returns a string containing the character represented by the int's value according to encoding.

65.chr    #=> "A"
230.chr   #=> "\xE6"
255.chr(Encoding::UTF_8)   #=> "\u00FF"
[ GitHub ]

  
# File 'numeric.c', line 3387

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, "%d 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 big represented as Bignum objects.

This is achieved by converting numeric to a Bignum.

A TypeError is raised if the numeric is not a Fixnum or Bignum type.

(0x3FFFFFFFFFFFFFFF+1).coerce(42)   #=> [42, 4611686018427387904]
[ GitHub ]

  
# File 'bignum.c', line 6769

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);
    }
}

#denominator1

Returns 1.

[ GitHub ]

  
# File 'rational.c', line 2067

static VALUE
integer_denominator(VALUE self)
{
    return INT2FIX(1);
}

#digitsArray #digits(base) ⇒ Array

Returns the digits of int's place-value representation with radix base (default: 10). The digits are returned as an array with the least significant digit as the first array element.

base must be greater than or equal to 2.

12345.digits      #=> [5, 4, 3, 2, 1]
12345.digits(7)   #=> [4, 6, 6, 0, 5]
12345.digits(100) #=> [45, 23, 1]

-12345.digits(7)  #=> Math::DomainError
[ GitHub ]

  
# File 'numeric.c', line 5009

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_TYPE_P(base_value, T_BIGNUM))
            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_TYPE_P(num, T_BIGNUM))
        return rb_int_digits_bigbase(num, LONG2FIX(base));

    return Qnil;
}

#div(numeric) ⇒ Integer

Performs integer division: returns the integer result of dividing int by numeric.

[ GitHub ]

  
# File 'numeric.c', line 3813

VALUE
rb_int_idiv(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_idiv(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_idiv(x, y);
    }
    return num_div(x, y);
}

#divmod(numeric) ⇒ Array

[ GitHub ]

  
# File 'numeric.c', line 3933

VALUE
rb_int_divmod(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_divmod(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_divmod(x, y);
    }
    return Qnil;
}

#downto(limit) {|i| ... } ⇒ self #downto(limit) ⇒ Enumerator

Iterates the given block, passing in decreasing values from int down to and including limit.

If no block is given, an ::Enumerator is returned instead.

5.downto(1) { |n| print n, ".. " }
puts "Liftoff!"
#=> "5.. 4.. 3.. 2.. 1.. Liftoff!"
[ GitHub ]

  
# File 'numeric.c', line 5109

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 floating point result of dividing int by numeric.

654321.fdiv(13731)      #=> 47.652829364212366
654321.fdiv(13731.24)   #=> 47.65199646936475
-654321.fdiv(13731)     #=> -47.652829364212366
[ GitHub ]

  
# File 'numeric.c', line 3731

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([ndigits]) ⇒ Integer, Float

Returns the largest number less than or equal to int with a precision of ndigits decimal digits (default: 0).

When the precision is negative, the returned value is an integer with at least ndigits.abs trailing zeros.

Returns self when ndigits is zero or positive.

1.floor           #=> 1
1.floor(2)        #=> 1
18.floor(-1)      #=> 10
(-18).floor(-1)   #=> -20
[ GitHub ]

  
# File 'numeric.c', line 5251

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
[ GitHub ]

  
# File 'rational.c', line 1891

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]
[ GitHub ]

  
# File 'rational.c', line 1929

VALUE
rb_gcdlcm(VALUE self, VALUE other)
{
    other = nurat_int_value(other);
    return rb_assoc_new(f_gcd(self, other), f_lcm(self, other));
}

#to_s(base = 10) ⇒ String #inspect(base = 10) ⇒ String

Alias for #to_s.

#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
[ GitHub ]

  
# File 'rational.c', line 1910

VALUE
rb_lcm(VALUE self, VALUE other)
{
    other = nurat_int_value(other);
    return f_lcm(self, other);
}

#magnitude

[ GitHub ]

  
# File 'integer.rb', line 29

def magnitude
  Primitive.attr! 'inline'
  Primitive.cexpr! 'rb_int_abs(self)'
end

#%(other) ⇒ Numeric #modulo(other) ⇒ Numeric

Alias for #%.

#nextInteger #succInteger
Also known as: #succ

Returns the successor of int, i.e. the Integer equal to int1</code>.

1.next      #=> 2
(-1).next   #=> 0
1.succ      #=> 2
(-1).succ   #=> 0
[ GitHub ]

  
# File 'numeric.c', line 3311

VALUE
rb_int_succ(VALUE num)
{
    if (FIXNUM_P(num)) {
	long i = FIX2LONG(num) + 1;
	return LONG2NUM(i);
    }
    if (RB_TYPE_P(num, T_BIGNUM)) {
	return rb_big_plus(num, INT2FIX(1));
    }
    return num_funcall1(num, '+', INT2FIX(1));
}

#nobits?(mask) ⇒ Boolean

Returns true if no bits of int & {mask} are 1.

[ GitHub ]

  
# File 'numeric.c', line 3288

static VALUE
int_nobits_p(VALUE num, VALUE mask)
{
    mask = rb_to_int(mask);
    return int_zero_p(rb_int_and(num, mask));
}

#numeratorself

Returns self.

[ GitHub ]

  
# File 'rational.c', line 2055

static VALUE
integer_numerator(VALUE self)
{
    return self;
}

#ordself

Returns the int itself.

97.ord   #=> 97

This method is intended for compatibility to character literals in Ruby 1.9.

For example, ?a.ord returns 97 both in 1.8 and 1.9.

[ GitHub ]

  
# File 'integer.rb', line 54

def ord
  return self
end

#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
[ GitHub ]

  
# File 'bignum.c', line 7131

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 <= 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();
            return int_pow_tmp3(rb_int_modulo(a, m), b, m, nega_flg);
        }
    }
    UNREACHABLE_RETURN(Qnil);
}

#predInteger

Returns the predecessor of int, i.e. the Integer equal to int-1.

1.pred      #=> 0
(-1).pred   #=> -2
[ GitHub ]

  
# File 'numeric.c', line 3337

static VALUE
rb_int_pred(VALUE num)
{
    if (FIXNUM_P(num)) {
	long i = FIX2LONG(num) - 1;
	return LONG2NUM(i);
    }
    if (RB_TYPE_P(num, T_BIGNUM)) {
	return rb_big_minus(num, INT2FIX(1));
    }
    return num_funcall1(num, '-', INT2FIX(1));
}

#rationalize([eps]) ⇒ Rational

Returns the value as a rational. The optional argument eps is always ignored.

[ GitHub ]

  
# File 'rational.c', line 2171

static VALUE
integer_rationalize(int argc, VALUE *argv, VALUE self)
{
    rb_check_arity(argc, 0, 1);
    return integer_to_r(self);
}

#remainder(numeric) ⇒ Numeric

Returns the remainder after dividing int by numeric.

x.remainder(y) means x-y*(x/y).truncate.

5.remainder(3)     #=> 2
-5.remainder(3)    #=> -2
5.remainder(-3)    #=> 2
-5.remainder(-3)   #=> -2
5.remainder(1.5)   #=> 0.5

See Numeric#divmod.

[ GitHub ]

  
# File 'numeric.c', line 3885

static VALUE
int_remainder(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return num_remainder(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_remainder(x, y);
    }
    return Qnil;
}

#round([ndigits] [, half: mode]) ⇒ Integer, Float

Returns int rounded to the nearest value with a precision of ndigits decimal digits (default: 0).

When the precision is negative, the returned value is an integer with at least ndigits.abs trailing zeros.

Returns self when ndigits is zero or positive.

1.round           #=> 1
1.round(2)        #=> 1
15.round(-1)      #=> 20
(-15).round(-1)   #=> -20

The optional half keyword argument is available similar to Float#round.

25.round(-1, half: :up)      #=> 30
25.round(-1, half: :down)    #=> 20
25.round(-1, half: :even)    #=> 20
35.round(-1, half: :up)      #=> 40
35.round(-1, half: :down)    #=> 30
35.round(-1, half: :even)    #=> 40
(-25).round(-1, half: :up)   #=> -30
(-25).round(-1, half: :down) #=> -20
(-25).round(-1, half: :even) #=> -20
[ GitHub ]

  
# File 'numeric.c', line 5216

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);
}

#sizeInteger

Returns the number of bytes in the machine representation of int (machine dependent).

1.size               #=> 8
-1.size              #=> 8
2147483647.size      #=> 8
(256**10 - 1).size   #=> 10
(256**20 - 1).size   #=> 20
(256**40 - 1).size   #=> 40
[ GitHub ]

  
# File 'numeric.c', line 4856

static VALUE
int_size(VALUE num)
{
    if (FIXNUM_P(num)) {
	return fix_size(num);
    }
    else if (RB_TYPE_P(num, T_BIGNUM)) {
	return rb_big_size_m(num);
    }
    return Qnil;
}

#nextInteger #succInteger

Alias for #next.

#times {|i| ... } ⇒ self #timesEnumerator

Iterates the given block int times, passing in values from zero to int - 1.

If no block is given, an ::Enumerator is returned instead.

5.times {|i| print i, " " }   #=> 0 1 2 3 4
[ GitHub ]

  
# File 'numeric.c', line 5159

static VALUE
int_dotimes(VALUE num)
{
    RETURN_SIZED_ENUMERATOR(num, 0, 0, int_dotimes_size);

    if (FIXNUM_P(num)) {
	long i, end;

	end = FIX2LONG(num);
	for (i=0; i<end; i++) {
	    rb_yield_1(LONG2FIX(i));
	}
    }
    else {
	VALUE i = INT2FIX(0);

	for (;;) {
	    if (!RTEST(rb_funcall(i, '<', 1, num))) break;
	    rb_yield(i);
	    i = rb_funcall(i, '+', 1, INT2FIX(1));
	}
    }
    return num;
}

#to_fFloat

Converts int to a ::Float. If int doesn't fit in a ::Float, the result is infinity.

[ GitHub ]

  
# File 'numeric.c', line 4778

static VALUE
int_to_f(VALUE num)
{
    double val;

    if (FIXNUM_P(num)) {
	val = (double)FIX2LONG(num);
    }
    else if (RB_TYPE_P(num, T_BIGNUM)) {
	val = rb_big2dbl(num);
    }
    else {
	rb_raise(rb_eNotImpError, "Unknown subclass for to_f: %s", rb_obj_classname(num));
    }

    return DBL2NUM(val);
}

#to_iInteger

Since int is already an Integer, returns self.

#to_int is an alias for #to_i.

[ GitHub ]

  
# File 'integer.rb', line 64

def to_i
  return self
end

#to_intInteger

Since int is already an Integer, returns self.

[ GitHub ]

  
# File 'integer.rb', line 72

def to_int
  return self
end

#to_rRational

Returns the value as a rational.

1.to_r        #=> (1/1)
(1<<64).to_r  #=> (18446744073709551616/1)
[ GitHub ]

  
# File 'rational.c', line 2158

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 int with radix base (between 2 and 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"
[ GitHub ]

  
# File 'numeric.c', line 3520

static VALUE
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]) ⇒ Integer, Float

Returns int truncated (toward zero) to a precision of ndigits decimal digits (default: 0).

When the precision is negative, the returned value is an integer with at least ndigits.abs trailing zeros.

Returns self when ndigits is zero or positive.

1.truncate           #=> 1
1.truncate(2)        #=> 1
18.truncate(-1)      #=> 10
(-18).truncate(-1)   #=> -10
[ GitHub ]

  
# File 'numeric.c', line 5315

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) ⇒ Enumerator

Iterates the given block, passing in integer values from int up to and including limit.

If no block is given, an ::Enumerator is returned instead.

5.upto(10) {|i| print i, " " }   #=> 5 6 7 8 9 10
[ GitHub ]

  
# File 'numeric.c', line 5063

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));
	}
	if (NIL_P(c)) rb_cmperr(i, to);
    }
    return from;
}

#|(other_int) ⇒ Integer

Bitwise OR.

[ GitHub ]

  
# File 'numeric.c', line 4469

static VALUE
int_or(VALUE x, VALUE y)
{
    if (FIXNUM_P(x)) {
	return fix_or(x, y);
    }
    else if (RB_TYPE_P(x, T_BIGNUM)) {
	return rb_big_or(x, y);
    }
    return Qnil;
}

#~Integer

One's complement: returns a number where each bit is flipped.

Inverts the bits in an Integer. As integers are 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)    #=> "..FEEDDCCBBAA"
[ GitHub ]

  
# File 'numeric.c', line 4370

static VALUE
int_comp(VALUE num)
{
    if (FIXNUM_P(num)) {
	return fix_comp(num);
    }
    else if (RB_TYPE_P(num, T_BIGNUM)) {
	return rb_big_comp(num);
    }
    return Qnil;
}