Synopsys¶ ↑
Enumerable#filter - extended Enumerable#select
Examples¶ ↑
String filter (acts like Enumerable#grep):
[1, 2, 3, 'ab'].filter(/a/) # => ['ab'] [1, 2, 3, '3'].filter('3') # => ['3']
You can pass a Proc or Symbol. Methods and blocks are allowed too:
[1, 2, 3].filter(&:even?) # => [2] [1, 2, 3].filter(:even?) # => [2] [1, 2, 4].filter { |num| num.even? } # => [2, 4]
Enumerable#filter can match against enumerable items attributes. Like this:
[1, 2, 3, 4.2].filter :to_i => :even? # => [2, 4]
If the block is supplied, each matching element is passed to it, and the block’s result is stored in the output array.
[1, 2, 4].filter(&:even?) { |n| n + 1 } # => [3, 5]
Enumerable#filter also accepts true or false as argument:
[0, false, 2, nil].filter(true) # => [0, 2] [0, false, 2, nil].filter(false) # => [false, nil]
Enumerable#filter also supports OR operator! Just pass many patterns, they will be joined together with OR operator.
[0, 2, 3, 4].filter(:zero?, :odd?) # => [0, 3]