Interesting Things

• min_by / max_by: Ian points us towards Enumerable‘s handy #min_by and #max_by. Want to get the string in a collection whose second-to-last character is earliest in the alphabet?

  ["ayx", "zbaaaz"].min_by { |s| s[-2] }  # => "zbaaaz"
  

• keep_if: On the subject of collections, Kris points out Ruby 1.9′s Array#keep_if (note the missing bang at the end), which mutates the array to remove things for which the block returns false. For example,

  a = ["ayx", "zbaaaz"]
  a.keep_if { |s| s.length < 4 }
  a                                       # => ["ayx"]
  

  Another method, Array#select! behaves very similarly. The only difference is that when it doesn’t change the array, #select! returns nil while #keep_if returns the array. Returning nil matches the behavior of other mutators like String#sub!, while #keep_if breaks the pattern. Thus,

  ["ayx", "zbaaaz"].keep_if { |s| s.length < 4 }    # => ["ayx"]
  ["ayx", "zbaaaz"].select! { |s| s.length < 4 }    # => ["ayx"]
  ["ayx", "zbaaaz"].keep_if { |s| s.length < 10 }   # => ["ayx", "zbaaaz"]
  ["ayx", "zbaaaz"].select! { |s| s.length < 10 }   # => nil
  

  It is, perhaps, of questionable value.

• $("textarea").clone(): Ian discovered that when jQuery clones form fields, the clones of input elements retain the values of the originals, while textareas and selects become blank.

• jsFiddle: Sam J. points us towards jsFiddle, a nifty tool for sharing JavaScript snippets. It provides a pane each for JS, CSS, and HTML, and then a pane that shows the results. Then you can share it like a Gist or a Pastie.