an example of Hash[ *ary1.zip(ary2).flatten ]

example.rb

require 'pp'

# say you've loaded a csv file with a header row, but you don't have
# access to any nice csv library. All you've got is an array of rows,
# which are also arrays:
#
# [
#   [ a, b, c, d ],
#   [ 1, 2, 3, 4 ],
#   [ 5, 6, 7, 8 ],
#   ...
# ]
#
# the first row is a header row, the rest are data. Then, you do this:

data = [
  [ :a, :b, :c, :d ],

  [ 1, 2, 3, 4 ],
  [ 5, 6, 7, 8 ],
  [ 0, 0, 0, 9 ],
]

headers = data.shift
pp data.map {|row| Hash[ *headers.zip(row).flatten ] }

# ta da!