Add Keys/Values from Strings or Arrays to a Ruby Hash
by Tilo Sloboda, 15 May 2007

  keysArr =   ["a", "b", "c", "d", "e", "f"]
  valuesArr = ["1", "2", "3", "4", "5", "6"]

  keysStr = "a b c d e f"
  valuesStr = "1,2,3,4,5,6"

  h1 = Hash.new.add_pairs(keysArr,valuesArr)
  => {"a"=>"1", "b"=>"2", "c"=>"3", "d"=>"4", "e"=>"5", "f"=>"6"}

  h2 = Hash.new.add_pairs(keysStr,valuesStr)
  => {"a"=>"1", "b"=>"2", "c"=>"3", "d"=>"4", "e"=>"5", "f"=>"6"}

  h3 = Hash.new.add_pairs(keysArr,valuesStr)
  => {"a"=>"1", "b"=>"2", "c"=>"3", "d"=>"4", "e"=>"5", "f"=>"6"}

  h4 = Hash.new.add_pairs(keysStr,valuesArr)
  => {"a"=>"1", "b"=>"2", "c"=>"3", "d"=>"4", "e"=>"5", "f"=>"6"}

Simple Solution

    keys = ["a", "b", "c", "d", "e", "f"]
    vals = [1, 2, 3, 4, 5, 6]

    h = Hash.new
    while k = keys.shift and v = vals.shift
      h[k] = v
    end
    => {"a"=>"1", "b"=>"2", "c"=>"3", "d"=>"4", "e"=>"5", "f"=>"6"}

    keys
    => []
    vals
    => []

More General Solution

    require "hash_add_pairs"

    keysArr =   ["a", "b", "c", "d", "e", "f"]
    valuesArr = ["1", "2", "3", "4", "5", "6"]

    keysStr = "a b c d e f"     WHITESPACE separated input string
    valuesStr = "1,2,3,4,5,6"	COMMA separated input string

    # input from two Arrays:

    h1 = Hash.new.add_pairs(keysArr,valuesArr)
    => {"a"=>"1", "b"=>"2", "c"=>"3", "d"=>"4", "e"=>"5", "f"=>"6"}

    # input from two Strings:
    #    please note that comma or space separated strings will be split automatically,
    #    without having to define a separator - commas have precedence over spaces.
    #    You can override this default-behaviour by explicitly defining a separator

    h2 = Hash.new.add_pairs(keysStr,valuesStr)
    => {"a"=>"1", "b"=>"2", "c"=>"3", "d"=>"4", "e"=>"5", "f"=>"6"}

    newkeyStr = "first key,second key,third key,fourth key,fifth key, sixth key"
    h = Hash.new.add_pairs(newKeyStr,valuesArr)
    => {"second key"=>"2", " sixth key"=>"6", "fifth key"=>"5", "first key"=>"1", "third key"=>"3", "fourth key"=>"4"}



    # MIXED input from Array and String:

    h3 = Hash.new.add_pairs(keysArr,valuesStr)
    => {"a"=>"1", "b"=>"2", "c"=>"3", "d"=>"4", "e"=>"5", "f"=>"6"}

    h4 = Hash.new.add_pairs(keysStr,valuesArr)
    => {"a"=>"1", "b"=>"2", "c"=>"3", "d"=>"4", "e"=>"5", "f"=>"6"}

    keysArr
    => ["a", "b", "c", "d", "e", "f"]
    valuesArr
    => ["1", "2", "3", "4", "5", "6"]
    keysStr
    => "a b c d e f"
    valuesStr
    => "1,2,3,4,5,6"

    # for Strings which are not using the commas or whitespace as separators:
    # please note that this also works for mixed inputs

    newKeys = "A:B:C:D:E:F"
    newVals = "1:2:3:4:5:6"

     h5 = Hash.new.add_pairs(newKeys,newVals,':')   # both Strings have to use the same separators
     => {"A"=>"1", "B"=>"2", "C"=>"3", "D"=>"4", "E"=>"5", "F"=>"6"}

     h6 = Hash.new.add_pairs(keysArr,newVals,':')
     => {"a"=>"1", "b"=>"2", "c"=>"3", "d"=>"4", "e"=>"5", "f"=>"6"}

     h7 = Hash.new.add_pairs(newKeys,valuesArr,':')
     => {"A"=>"1", "B"=>"2", "C"=>"3", "D"=>"4", "E"=>"5", "F"=>"6"}

NOTES

• If you provide less values than keys, the remaining values will default to nil
• If you provide less keys than values, any remaining values will be ignored
• If you provide strings as an input, they will automatically split if they contain either commas or spaces.
• Commas have precedence over spaces, in case you use the automatic splitting
• You can override this behaviour by explicitly defining a separator string
• If you provide a separator string or RegExp and have Strings for the keys and values, then the same separator will be used for both strings.
• If you (accidentially?) provide a separator string, and have two Arrays as inputs, the separator will be ignored

Download hash_add_pairs.rb

Details

I'm not sure about the naming of those two methods yet - if you have suggestions how to rename them please contact me at

    myFirstname dot myLastname at GMail.com

Please see the source code of the file for more details.

License