Useful Iterators and Methods for Ruby on Rails

When you want to travel through the items in a database you created with Ruby on Rails, knowing the iterators to use is key. The following table shows helpful iterators and methods:































































[1, 2, 3].each { }=> [1, 2, 3]
[1, nil, nil, 2, 3, nil].compact { }=> [1, 2, 3]
[1, 2, 3].delete_if { |x| x >= 3 }=> [1, 2]
[1, 2, 3].collect { |x| x + 1 }=> [2, 3, 4]
[1, 2, 3].find_all { |x| x % 2 == 1 }=> [1, 3]
[1, 2, 3].reject { |x| x % 2 == 1 }=> [2]
[2, 5, 1, 0, 7].sort=> [0, 1, 2, 5, 7]
[2, 5, 1, 0, 7].max=> 7
[1, [2, 3]].flatten=> [1, 2, 3]
[1, 2, 3].empty?=> false
[].empty?=> true
[0, 5, 9].length=> 3
[1, 2, 3].include?(2)=> true
[1, 2, 3].include?(16)=> false
[1, 2, 3].reverse=> [3, 2, 1]








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Source:http://www.dummies.com/how-to/content/useful-iterators-and-methods-for-ruby-on-rails.navId-323192.html

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