By using binary search, finds an index of a value from this array which meets the given condition in O(log n) where n is the size of the array.
It supports two modes, depending on the nature of the block. They are exactly the same as in the case of the bsearch method, with the only difference being that this method returns the index of the element instead of the element itself. For more details consult the documentation for bsearch.
Tries to convert obj into an array, using the to_ary method. Returns the converted array or nil if obj cannot be converted. This method can be used to check if an argument is an array.
Array.try_convert([1]) #=> [1] Array.try_convert("1") #=> nil if tmp = Array.try_convert(arg) # the argument is an array elsif tmp = String.try_convert(arg) # the argument is a string end
Replaces the contents of self with the contents of other_ary, truncating or expanding if necessary.
a = [ "a", "b", "c", "d", "e" ] a.replace([ "x", "y", "z" ]) #=> ["x", "y", "z"] a #=> ["x", "y", "z"]
Returns the result of interpreting ary as an array of [key, value] pairs.
[[:foo, :bar], [1, 2]].to_h # => {:foo => :bar, 1 => 2}
If a block is given, the results of the block on each element of the array will be used as pairs.
["foo", "bar"].to_h {|s| [s.ord, s]} # => {102=>"foo", 98=>"bar"}
Same as Array#each, but passes the index of the element instead of the element itself.
An Enumerator is returned if no block is given.
a = [ "a", "b", "c" ] a.each_index {|x| print x, " -- " }
produces:
0 -- 1 -- 2 --
Same as Array#each, but traverses self in reverse order.
a = [ "a", "b", "c" ] a.reverse_each {|x| print x, " " }
produces:
c b a
Returns the index of the first object in ary such that the object is == to obj.
If a block is given instead of an argument, returns the index of the first object for which the block returns true. Returns nil if no match is found.
See also Array#rindex.
An Enumerator is returned if neither a block nor argument is given.
a = [ "a", "b", "c" ] a.index("b") #=> 1 a.index("z") #=> nil a.index {|x| x == "b"} #=> 1
Sorts self in place using a set of keys generated by mapping the values in self through the given block.
The result is not guaranteed to be stable. When two keys are equal, the order of the corresponding elements is unpredictable.
If no block is given, an Enumerator is returned instead.
See also Enumerable#sort_by.
Deletes every element of self for which the given block evaluates to false, and returns self.
If no block is given, an Enumerator is returned instead.
a = %w[ a b c d e f ] a.keep_if {|v| v =~ /[aeiou]/ } #=> ["a", "e"] a #=> ["a", "e"]
See also Array#select!.
Returns an array containing the elements in self corresponding to the given selector(s).
The selectors may be either integer indices or ranges.
See also Array#select.
a = %w{ a b c d e f } a.values_at(1, 3, 5) # => ["b", "d", "f"] a.values_at(1, 3, 5, 7) # => ["b", "d", "f", nil] a.values_at(-1, -2, -2, -7) # => ["f", "e", "e", nil] a.values_at(4..6, 3...6) # => ["e", "f", nil, "d", "e", "f"]
Deletes the element at the specified index, returning that element, or nil if the index is out of range.
See also Array#slice!
a = ["ant", "bat", "cat", "dog"] a.delete_at(2) #=> "cat" a #=> ["ant", "bat", "dog"] a.delete_at(99) #=> nil
Deletes every element of self for which block evaluates to true.
The array is changed instantly every time the block is called, not after the iteration is over.
See also Array#reject!
If no block is given, an Enumerator is returned instead.
scores = [ 97, 42, 75 ] scores.delete_if {|score| score < 80 } #=> [97]
When invoked with a block, yield all repeated permutations of length n of the elements of the array, then return the array itself.
The implementation makes no guarantees about the order in which the repeated permutations are yielded.
If no block is given, an Enumerator is returned instead.
Examples:
a = [1, 2] a.repeated_permutation(1).to_a #=> [[1], [2]] a.repeated_permutation(2).to_a #=> [[1,1],[1,2],[2,1],[2,2]] a.repeated_permutation(3).to_a #=> [[1,1,1],[1,1,2],[1,2,1],[1,2,2], # [2,1,1],[2,1,2],[2,2,1],[2,2,2]] a.repeated_permutation(0).to_a #=> [[]] # one permutation of length 0
When invoked with a block, yields all repeated combinations of length n of elements from the array and then returns the array itself.
The implementation makes no guarantees about the order in which the repeated combinations are yielded.
If no block is given, an Enumerator is returned instead.
Examples:
a = [1, 2, 3] a.repeated_combination(1).to_a #=> [[1], [2], [3]] a.repeated_combination(2).to_a #=> [[1,1],[1,2],[1,3],[2,2],[2,3],[3,3]] a.repeated_combination(3).to_a #=> [[1,1,1],[1,1,2],[1,1,3],[1,2,2],[1,2,3], # [1,3,3],[2,2,2],[2,2,3],[2,3,3],[3,3,3]] a.repeated_combination(4).to_a #=> [[1,1,1,1],[1,1,1,2],[1,1,1,3],[1,1,2,2],[1,1,2,3], # [1,1,3,3],[1,2,2,2],[1,2,2,3],[1,2,3,3],[1,3,3,3], # [2,2,2,2],[2,2,2,3],[2,2,3,3],[2,3,3,3],[3,3,3,3]] a.repeated_combination(0).to_a #=> [[]] # one combination of length 0
Passes elements to the block until the block returns nil or false, then stops iterating and returns an array of all prior elements.
If no block is given, an Enumerator is returned instead.
See also Array#drop_while
a = [1, 2, 3, 4, 5, 0] a.take_while {|i| i < 3} #=> [1, 2]
Drops elements up to, but not including, the first element for which the block returns nil or false and returns an array containing the remaining elements.
If no block is given, an Enumerator is returned instead.
See also Array#take_while
a = [1, 2, 3, 4, 5, 0] a.drop_while {|i| i < 3 } #=> [3, 4, 5, 0]
Creates a string representation of self, by calling inspect on each element.
[ "a", "b", "c" ].to_s #=> "[\"a\", \"b\", \"c\"]"
Return the list of all array-oriented instance variables.
Returns a new string object containing a copy of str.
The optional encoding keyword argument specifies the encoding of the new string. If not specified, the encoding of str is used (or ASCII-8BIT, if str is not specified).
The optional capacity keyword argument specifies the size of the internal buffer. This may improve performance, when the string will be concatenated many times (causing many realloc calls).
Returns a new directory object for the named directory.
The optional encoding keyword argument specifies the encoding of the directory. If not specified, the filesystem encoding is used.