Returns elements from self, or nil; self is not modified.
With no argument given, returns the last element, or nil if self is empty:
a = [:foo, 'bar', 2] a.last # => 2 a # => [:foo, "bar", 2] [].last # => nil
With non-negative integer argument count given, returns a new array containing the trailing count elements of self, as available:
a = [:foo, 'bar', 2] a.last(2) # => ["bar", 2] a.last(50) # => [:foo, "bar", 2] a.last(0) # => [] [].last(3) # => []
Related: see Methods for Fetching.
Returns a Hash containing implementation-dependent counters inside the VM.
This hash includes information about method/constant caches:
{
:constant_cache_invalidations=>2,
:constant_cache_misses=>14,
:global_cvar_state=>27
}
If USE_DEBUG_COUNTER is enabled, debug counters will be included.
The contents of the hash are implementation specific and may be changed in the future.
This method is only expected to work on C Ruby.
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.
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.
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.
Returns the predecessor of self (equivalent to self - 1):
1.pred #=> 0 -1.pred #=> -2
Related: Integer#succ (successor value).
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
Returns an integer that is a “floor” 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 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.
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)
Returns self; intended for compatibility to character literals in Ruby 1.9.
Returns self (which is already an Integer).
Returns the value as a rational.
1.to_r #=> (1/1) (1<<64).to_r #=> (18446744073709551616/1)
Returns a new Complex object formed from the arguments, each of which must be an instance of Numeric, or an instance of one of its subclasses: Complex, Float, Integer, Rational; see Rectangular Coordinates:
Complex.rect(3) # => (3+0i) Complex.rect(3, Math::PI) # => (3+3.141592653589793i) Complex.rect(-3, -Math::PI) # => (-3-3.141592653589793i)
Complex.rectangular is an alias for Complex.rect.
Returns a new Complex object formed from the arguments, each of which must be an instance of Numeric, or an instance of one of its subclasses: Complex, Float, Integer, Rational; see Rectangular Coordinates:
Complex.rect(3) # => (3+0i) Complex.rect(3, Math::PI) # => (3+3.141592653589793i) Complex.rect(-3, -Math::PI) # => (-3-3.141592653589793i)
Complex.rectangular is an alias for Complex.rect.
Returns the real value for self:
Complex.rect(7).real # => 7 Complex.rect(9, -4).real # => 9
If self was created with polar coordinates, the returned value is computed, and may be inexact:
Complex.polar(1, Math::PI/4).real # => 0.7071067811865476 # Square root of 2.
Returns the array [self.real, self.imag]:
Complex.rect(1, 2).rect # => [1, 2]
If self was created with polar coordinates, the returned value is computed, and may be inexact:
Complex.polar(1.0, 1.0).rect # => [0.5403023058681398, 0.8414709848078965]
Complex#rectangular is an alias for Complex#rect.
Returns a new Complex object formed from the arguments, each of which must be an instance of Numeric, or an instance of one of its subclasses: Complex, Float, Integer, Rational; see Rectangular Coordinates:
Complex.rect(3) # => (3+0i) Complex.rect(3, Math::PI) # => (3+3.141592653589793i) Complex.rect(-3, -Math::PI) # => (-3-3.141592653589793i)
Complex.rectangular is an alias for Complex.rect.
Returns false; for compatibility with Numeric#real?.
Returns a string representation of self:
Complex.rect(2).to_s # => "2+0i" Complex.rect(-8, 6).to_s # => "-8+6i" Complex.rect(0, Rational(1, 2)).to_s # => "0+1/2i" Complex.rect(0, Float::INFINITY).to_s # => "0+Infinity*i" Complex.rect(Float::NAN, Float::NAN).to_s # => "NaN+NaN*i"
Returns the value of self.real as an Integer, if possible:
Complex.rect(1, 0).to_i # => 1 Complex.rect(1, Rational(0, 1)).to_i # => 1
Raises RangeError if self.imag is not exactly zero (either Integer(0) or Rational(0, n)).
Returns the value of self.real as a Float, if possible:
Complex.rect(1, 0).to_f # => 1.0 Complex.rect(1, Rational(0, 1)).to_f # => 1.0
Raises RangeError if self.imag is not exactly zero (either Integer(0) or Rational(0, n)).
Returns the value of self.real as a Rational, if possible:
Complex.rect(1, 0).to_r # => (1/1) Complex.rect(1, Rational(0, 1)).to_r # => (1/1) Complex.rect(1, 0.0).to_r # => (1/1)
Raises RangeError if self.imag is not exactly zero (either Integer(0) or Rational(0, n)) and self.imag.to_r is not exactly zero.
Related: Complex#rationalize.
Returns self.