How to build a Ruby hash out of two equally-sized arrays?
RubyArraysHashRuby Problem Overview
I have two arrays
a = [:foo, :bar, :baz, :bof]
and
b = ["hello", "world", 1, 2]
I want
{:foo => "hello", :bar => "world", :baz => 1, :bof => 2}
Any way to do this?
Ruby Solutions
Solution 1 - Ruby
h = Hash[a.zip b] # => {:baz=>1, :bof=>2, :bar=>"world", :foo=>"hello"}
...damn, I love Ruby.
Solution 2 - Ruby
Just wanted to point out that there's a slightly cleaner way of doing this:
h = a.zip(b).to_h # => {:foo=>"hello", :bar=>"world", :baz=>1, :bof=>2}
Have to agree on the "I love Ruby" part though!
Solution 3 - Ruby
How about this one?
[a, b].transpose.to_h
If you use Ruby 1.9:
Hash[ [a, b].transpose ]
I feel a.zip(b) looks like a is master and b is slave, but in this style they are flat.
Solution 4 - Ruby
Just for curiosity's sake:
require 'fruity'
a = [:foo, :bar, :baz, :bof]
b = ["hello", "world", 1, 2]
compare do
jtbandes { h = Hash[a.zip b] }
lethjakman { h = a.zip(b).to_h }
junichi_ito1 { [a, b].transpose.to_h }
junichi_ito2 { Hash[ [a, b].transpose ] }
end
# >> Running each test 8192 times. Test will take about 1 second.
# >> lethjakman is similar to junichi_ito1
# >> junichi_ito1 is similar to jtbandes
# >> jtbandes is similar to junichi_ito2
compare do
junichi_ito1 { [a, b].transpose.to_h }
junichi_ito2 { Hash[ [a, b].transpose ] }
end
# >> Running each test 8192 times. Test will take about 1 second.
# >> junichi_ito1 is faster than junichi_ito2 by 19.999999999999996% ± 10.0%