Question

@main = connection.execute("select code_ver, comment from mastertest 

@main contains something like this :

{ [2.1, abcd],
  [3.0, xyz],
  [2.0, pqr] }

I want to split this array into 2 arrays such that:

@arr1 = {[2.1],
         [3.0],
         [2.0]}

@arr2 = {[abcd],
         [xyz],
         [pqr]}

I do something like this to copy one array from another one:

@arr1 = Array.new
@main.each { |r| @arr1.push(r[0]) }

Can something be done here itself to split it how I want it?

Answer 1

Assuming there were some typo’s in your “array” above, a simple map will do the trick:

> @main = [[2.1, 'abcd'], [3.0, 'xyz'], [2.0, 'pqr']]
# => [[2.1, "abcd"], [3.0, "xyz"], [2.0, "pqr"]] 
> @arr1 = @main.map {|y|[y[0]]}
# => [[2.1], [3.0], [2.0]] 
> @arr2 = @main.map {|y|[y[1]]}
# => [["abcd"], ["xyz"], ["pqr"]] 

You might also look at transpose:

> @main.transpose
# => [[2.1, 3.0, 2.0], ["abcd", "xyz", "pqr"]]