Question

I read (in the documentation) how to concatenate the strings of one array with another string:

a = [ "a", "b", "c", "d" ]
a.collect! {|x| x + "!" }
a                          #=>  [ "a!", "b!", "c!", "d!" ]

but what I haven’t figured out is how to concatenate the strings of 2 arrays into one. For example:

field_suffix = %w[prev curr]
field_names = %w[_first_name _last_name]

What I’d like to see is this:

["prev_first_name", "curr_first_name", "prev_last_name", "curr_last_name"]

The order doesn’t matter. It could be:

["prev_first_name", "prev_last_name", "curr_first_name", "curr_last_name"]

Answer 1

I would do it with the following:

out=[]
pre=["sub", "pre"]
suf=["less", "ness"]
pre.each do |p|
  suf.each do |s|
    out.push(p+s)
  end
end
puts out

Or in less lines:

out=[]
pre=["sub", "pre"]
suf=["less", "ness"]
pre.each{|p| suf.each{|s| out.push(p+s)}}

This will not return the array (sadly), you have to have the second array; out which will be subless, subness, preless, preness