in “” in “foo”
in :+ in :foo
Check state file is writable. Creates empty file if not present to ensure we can write to it.
The location of the default spec file for default gems.
foo rescue bar ^^^^^^^^^^^^^^
Parse a rational from the string representation.
Returns the count of elements in self:
[0, 1, 2].length # => 3 [].length # => 0
Related: see Methods for Querying.
Removes zero or more elements from self.
With no block given, removes from self each element ele such that ele == object; returns the last removed element:
a = [0, 1, 2, 2.0] a.delete(2) # => 2.0 a # => [0, 1]
Returns nil if no elements removed:
a.delete(2) # => nil
With a block given, removes from self each element ele such that ele == object.
If any such elements are found, ignores the block and returns the last removed element:
a = [0, 1, 2, 2.0] a.delete(2) {|element| fail 'Cannot happen' } # => 2.0 a # => [0, 1]
If no such element is found, returns the block’s return value:
a.delete(2) {|element| "Element #{element} not found." } # => "Element 2 not found."
Related: see Methods for Deleting.
Removes all elements from self; returns self:
a = [:foo, 'bar', 2] a.clear # => []
Related: see Methods for Deleting.
With a block given, may call the block, depending on the value of argument count; count must be an integer-convertible object, or nil.
When count is positive, calls the block with each element, then does so repeatedly, until it has done so count times; returns nil:
output = [] [0, 1].cycle(2) {|element| output.push(element) } # => nil output # => [0, 1, 0, 1]
When count is zero or negative, does not call the block:
[0, 1].cycle(0) {|element| fail 'Cannot happen' } # => nil [0, 1].cycle(-1) {|element| fail 'Cannot happen' } # => nil
When count is nil, cycles forever:
# Prints 0 and 1 forever. [0, 1].cycle {|element| puts element } [0, 1].cycle(nil) {|element| puts element }
With no block given, returns a new Enumerator.
Related: see Methods for Iterating.
Shuffles all elements in self into a random order, as selected by the object given by the keyword argument random. Returns self:
a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] a.shuffle! # => [5, 3, 8, 7, 6, 1, 9, 4, 2, 0] a.shuffle! # => [9, 4, 0, 6, 2, 8, 1, 5, 3, 7]
Duplicate elements are included:
a = [0, 1, 0, 1, 0, 1, 0, 1, 0, 1] a.shuffle! # => [1, 0, 0, 1, 1, 0, 1, 0, 0, 1] a.shuffle! # => [0, 1, 0, 1, 1, 0, 1, 0, 1, 0]
The object given with the keyword argument random is used as the random number generator.
Related: see Methods for Assigning.
Returns a new array containing all elements from self in a random order, as selected by the object given by the keyword argument random:
a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] a.shuffle # => [0, 8, 1, 9, 6, 3, 4, 7, 2, 5] a.shuffle # => [8, 9, 0, 5, 1, 2, 6, 4, 7, 3]
Duplicate elements are included:
a = [0, 1, 0, 1, 0, 1, 0, 1, 0, 1] a.shuffle # => [1, 0, 1, 1, 0, 0, 1, 0, 0, 1] a.shuffle # => [1, 1, 0, 0, 0, 1, 1, 0, 0, 1]
The object given with the keyword argument random is used as the random number generator.
Related: see Methods for Fetching.
Returns random elements from self, as selected by the object given by the keyword argument random.
With no argument count given, returns one random element from self:
a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] a.sample # => 3 a.sample # => 8
Returns nil if self is empty:
[].sample # => nil
With a non-negative numeric argument count given, returns a new array containing count random elements from self:
a.sample(3) # => [8, 9, 2] a.sample(6) # => [9, 6, 0, 3, 1, 4]
The order of the result array is unrelated to the order of self.
Returns a new empty array if self is empty:
[].sample(4) # => []
May return duplicates in self:
a = [1, 1, 1, 2, 2, 3] a.sample(a.size) # => [1, 1, 3, 2, 1, 2]
Returns no more than a.size elements (because no new duplicates are introduced):
a.sample(50) # => [6, 4, 1, 8, 5, 9, 0, 2, 3, 7]
The object given with the keyword argument random is used as the random number generator:
a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] a.sample(random: Random.new(1)) # => 6 a.sample(4, random: Random.new(1)) # => [6, 10, 9, 2]
Related: see Methods for Fetching.
Returns true if self is an odd number, false otherwise.
Returns the argument (angle) for self in radians; see polar coordinates:
Complex.polar(3, Math::PI/2).arg # => 1.57079632679489660
If self was created with rectangular coordinates, the returned value is computed, and may be inexact:
Complex.polar(1, 1.0/3).arg # => 0.33333333333333326
Returns zero if self is positive, Math::PI otherwise.
Escapes str so that it can be safely used in a Bourne shell command line.
See Shellwords.shellescape for details.
Returns the count of characters (not bytes) in self:
'foo'.length # => 3 'тест'.length # => 4 'こんにちは'.length # => 5
Contrast with String#bytesize:
'foo'.bytesize # => 3 'тест'.bytesize # => 8 'こんにちは'.bytesize # => 15
Returns a printable version of self, enclosed in double-quotes, with special characters escaped, and with non-printing characters replaced by hexadecimal notation:
"hello \n ''".dump # => "\"hello \\n ''\"" "\f\x00\xff\\\"".dump # => "\"\\f\\x00\\xFF\\\\\\\"\""
Related: String#undump (inverse of String#dump).
Returns an array of the codepoints in self; each codepoint is the integer value for a character:
'hello'.codepoints # => [104, 101, 108, 108, 111] 'тест'.codepoints # => [1090, 1077, 1089, 1090] 'こんにちは'.codepoints # => [12371, 12435, 12395, 12385, 12399]