Calls the block, if given, with each element of self; returns a new Array whose elements are the return values from the block:
a = [:foo, 'bar', 2] a1 = a.map {|element| element.class } a1 # => [Symbol, String, Integer]
Returns a new Enumerator if no block given:
a = [:foo, 'bar', 2] a1 = a.map a1 # => #<Enumerator: [:foo, "bar", 2]:map>
Array#collect is an alias for Array#map.
Calls the block, if given, with each element; replaces the element with the block’s return value:
a = [:foo, 'bar', 2] a.map! { |element| element.class } # => [Symbol, String, Integer]
Returns a new Enumerator if no block given:
a = [:foo, 'bar', 2] a1 = a.map! a1 # => #<Enumerator: [:foo, "bar", 2]:map!>
Array#collect! is an alias for Array#map!.
Replaces specified elements in self with specified objects; returns self.
With argument obj and no block given, replaces all elements with that one object:
a = ['a', 'b', 'c', 'd'] a # => ["a", "b", "c", "d"] a.fill(:X) # => [:X, :X, :X, :X]
With arguments obj and Integer start, and no block given, replaces elements based on the given start.
If start is in range (0 <= start < array.size), replaces all elements from offset start through the end:
a = ['a', 'b', 'c', 'd'] a.fill(:X, 2) # => ["a", "b", :X, :X]
If start is too large (start >= array.size), does nothing:
a = ['a', 'b', 'c', 'd'] a.fill(:X, 4) # => ["a", "b", "c", "d"] a = ['a', 'b', 'c', 'd'] a.fill(:X, 5) # => ["a", "b", "c", "d"]
If start is negative, counts from the end (starting index is start + array.size):
a = ['a', 'b', 'c', 'd'] a.fill(:X, -2) # => ["a", "b", :X, :X]
If start is too small (less than and far from zero), replaces all elements:
a = ['a', 'b', 'c', 'd'] a.fill(:X, -6) # => [:X, :X, :X, :X] a = ['a', 'b', 'c', 'd'] a.fill(:X, -50) # => [:X, :X, :X, :X]
With arguments obj, Integer start, and Integer length, and no block given, replaces elements based on the given start and length.
If start is in range, replaces length elements beginning at offset start:
a = ['a', 'b', 'c', 'd'] a.fill(:X, 1, 1) # => ["a", :X, "c", "d"]
If start is negative, counts from the end:
a = ['a', 'b', 'c', 'd'] a.fill(:X, -2, 1) # => ["a", "b", :X, "d"]
If start is large (start >= array.size), extends self with nil:
a = ['a', 'b', 'c', 'd'] a.fill(:X, 5, 0) # => ["a", "b", "c", "d", nil] a = ['a', 'b', 'c', 'd'] a.fill(:X, 5, 2) # => ["a", "b", "c", "d", nil, :X, :X]
If length is zero or negative, replaces no elements:
a = ['a', 'b', 'c', 'd'] a.fill(:X, 1, 0) # => ["a", "b", "c", "d"] a.fill(:X, 1, -1) # => ["a", "b", "c", "d"]
With arguments obj and Range range, and no block given, replaces elements based on the given range.
If the range is positive and ascending (0 < range.begin <= range.end), replaces elements from range.begin to range.end:
a = ['a', 'b', 'c', 'd'] a.fill(:X, (1..1)) # => ["a", :X, "c", "d"]
If range.first is negative, replaces no elements:
a = ['a', 'b', 'c', 'd'] a.fill(:X, (-1..1)) # => ["a", "b", "c", "d"]
If range.last is negative, counts from the end:
a = ['a', 'b', 'c', 'd'] a.fill(:X, (0..-2)) # => [:X, :X, :X, "d"] a = ['a', 'b', 'c', 'd'] a.fill(:X, (1..-2)) # => ["a", :X, :X, "d"]
If range.last and range.last are both negative, both count from the end of the array:
a = ['a', 'b', 'c', 'd'] a.fill(:X, (-1..-1)) # => ["a", "b", "c", :X] a = ['a', 'b', 'c', 'd'] a.fill(:X, (-2..-2)) # => ["a", "b", :X, "d"]
With no arguments and a block given, calls the block with each index; replaces the corresponding element with the block’s return value:
a = ['a', 'b', 'c', 'd'] a.fill { |index| "new_#{index}" } # => ["new_0", "new_1", "new_2", "new_3"]
With argument start and a block given, calls the block with each index from offset start to the end; replaces the corresponding element with the block’s return value:
If start is in range (0 <= start < array.size), replaces from offset start to the end:
a = ['a', 'b', 'c', 'd'] a.fill(1) { |index| "new_#{index}" } # => ["a", "new_1", "new_2", "new_3"]
If start is too large(start >= array.size), does nothing:
a = ['a', 'b', 'c', 'd'] a.fill(4) { |index| fail 'Cannot happen' } # => ["a", "b", "c", "d"] a = ['a', 'b', 'c', 'd'] a.fill(4) { |index| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
If start is negative, counts from the end:
a = ['a', 'b', 'c', 'd'] a.fill(-2) { |index| "new_#{index}" } # => ["a", "b", "new_2", "new_3"]
If start is too small (start <= -array.size, replaces all elements:
a = ['a', 'b', 'c', 'd'] a.fill(-6) { |index| "new_#{index}" } # => ["new_0", "new_1", "new_2", "new_3"] a = ['a', 'b', 'c', 'd'] a.fill(-50) { |index| "new_#{index}" } # => ["new_0", "new_1", "new_2", "new_3"]
With arguments start and length, and a block given, calls the block for each index specified by start length; replaces the corresponding element with the block’s return value.
If start is in range, replaces length elements beginning at offset start:
a = ['a', 'b', 'c', 'd'] a.fill(1, 1) { |index| "new_#{index}" } # => ["a", "new_1", "c", "d"]
If start is negative, counts from the end:
a = ['a', 'b', 'c', 'd'] a.fill(-2, 1) { |index| "new_#{index}" } # => ["a", "b", "new_2", "d"]
If start is large (start >= array.size), extends self with nil:
a = ['a', 'b', 'c', 'd'] a.fill(5, 0) { |index| "new_#{index}" } # => ["a", "b", "c", "d", nil] a = ['a', 'b', 'c', 'd'] a.fill(5, 2) { |index| "new_#{index}" } # => ["a", "b", "c", "d", nil, "new_5", "new_6"]
If length is zero or less, replaces no elements:
a = ['a', 'b', 'c', 'd'] a.fill(1, 0) { |index| "new_#{index}" } # => ["a", "b", "c", "d"] a.fill(1, -1) { |index| "new_#{index}" } # => ["a", "b", "c", "d"]
With arguments obj and range, and a block given, calls the block with each index in the given range; replaces the corresponding element with the block’s return value.
If the range is positive and ascending (range 0 < range.begin <= range.end, replaces elements from range.begin to range.end:
a = ['a', 'b', 'c', 'd'] a.fill(1..1) { |index| "new_#{index}" } # => ["a", "new_1", "c", "d"]
If range.first is negative, does nothing:
a = ['a', 'b', 'c', 'd'] a.fill(-1..1) { |index| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
If range.last is negative, counts from the end:
a = ['a', 'b', 'c', 'd'] a.fill(0..-2) { |index| "new_#{index}" } # => ["new_0", "new_1", "new_2", "d"] a = ['a', 'b', 'c', 'd'] a.fill(1..-2) { |index| "new_#{index}" } # => ["a", "new_1", "new_2", "d"]
If range.first and range.last are both negative, both count from the end:
a = ['a', 'b', 'c', 'd'] a.fill(-1..-1) { |index| "new_#{index}" } # => ["a", "b", "c", "new_3"] a = ['a', 'b', 'c', 'd'] a.fill(-2..-2) { |index| "new_#{index}" } # => ["a", "b", "new_2", "d"]
When invoked with a block, yield all permutations of elements of self; returns self. The order of permutations is indeterminate.
When a block and an in-range positive Integer argument n (0 < n <= self.size) are given, calls the block with all n-tuple permutations of self.
Example:
a = [0, 1, 2] a.permutation(2) {|permutation| p permutation }
Output:
[0, 1] [0, 2] [1, 0] [1, 2] [2, 0] [2, 1]
Another example:
a = [0, 1, 2] a.permutation(3) {|permutation| p permutation }
Output:
[0, 1, 2] [0, 2, 1] [1, 0, 2] [1, 2, 0] [2, 0, 1] [2, 1, 0]
When n is zero, calls the block once with a new empty Array:
a = [0, 1, 2] a.permutation(0) {|permutation| p permutation }
Output:
[]
When n is out of range (negative or larger than self.size), does not call the block:
a = [0, 1, 2] a.permutation(-1) {|permutation| fail 'Cannot happen' } a.permutation(4) {|permutation| fail 'Cannot happen' }
When a block given but no argument, behaves the same as a.permutation(a.size):
a = [0, 1, 2] a.permutation {|permutation| p permutation }
Output:
[0, 1, 2] [0, 2, 1] [1, 0, 2] [1, 2, 0] [2, 0, 1] [2, 1, 0]
Returns a new Enumerator if no block given:
a = [0, 1, 2] a.permutation # => #<Enumerator: [0, 1, 2]:permutation> a.permutation(2) # => #<Enumerator: [0, 1, 2]:permutation(2)>
Returns a new Array containing the first n element of self, where n is a non-negative Integer; does not modify self.
Examples:
a = [0, 1, 2, 3, 4, 5] a.take(1) # => [0] a.take(2) # => [0, 1] a.take(50) # => [0, 1, 2, 3, 4, 5] a # => [0, 1, 2, 3, 4, 5]
Builds a command line string from an argument list array joining all elements escaped for the Bourne shell and separated by a space.
See Shellwords.shelljoin for details.
Returns a Hash containing implementation-dependent counters inside the VM.
This hash includes information about method/constant cache serials:
{
:global_constant_state=>481,
:class_serial=>9029
}
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 object. This method is deprecated and will be removed in Ruby 3.2.
Returns false. This method is deprecated and will be removed in Ruby 3.2.
Returns object. This method is deprecated and will be removed in Ruby 3.2.
Returns the value as a rational. The optional argument eps is always ignored.
Returns a complex object which denotes the given rectangular form.
Complex.rectangular(1, 2) #=> (1+2i)
Returns false, even if the complex number has no imaginary part.
Returns the value as a rational if possible (the imaginary part should be exactly zero).
Complex(1.0/3, 0).rationalize #=> (1/3) Complex(1, 0.0).rationalize # RangeError Complex(1, 2).rationalize # RangeError
See to_r.
Returns zero as a rational. The optional argument eps is always ignored.
Returns self.
Returns an array; [num, 0].
Returns true if num is a real number (i.e. not Complex).
Convert self to locale encoding
Splits str into an array of tokens in the same way the UNIX Bourne shell does.
See Shellwords.shellsplit for details.
Escapes str so that it can be safely used in a Bourne shell command line.
See Shellwords.shellescape for details.
Returns a simpler approximation of the value (flt-|eps| <= result <= flt+|eps|). If the optional argument eps is not given, it will be chosen automatically.
0.3.rationalize #=> (3/10) 1.333.rationalize #=> (1333/1000) 1.333.rationalize(0.01) #=> (4/3)
See also Float#to_r.
Returns true if the fiber can still be resumed (or transferred to). After finishing execution of the fiber block this method will always return false. You need to require 'fiber' before using this method.