Re: how to refer the index of an array to another array of the same length

[rjt]

I want to print all the occurrence of @cg in @gl and for the corresponding index of matched @gl, i want to print @csta

Sounds like a perfect job for hashes, especially if your inputs are non-trivially large. Given @gl and @csta are of equal length, List::MoreUtils will work nicely:

#!/usr/bin/env perl

use 5.012;
use warnings FATAL => 'all';

use List::MoreUtils qw/zip/;

my @cg   = (qw<one two three four five>);
my @gl   = (qw<two four five>);
my @csta = (qw<II  IV   V>);

my %gl_csta = (zip @gl, @csta);

printf "%5s => %s\n", $_, $gl_csta{$_} 
    for grep { exists $gl_csta{$_} } @cg;

Output:

  two => II
 four => IV
 five => V