There are multiple things wrong here.
Your code should always start with:
use warnings;
use strict;

[download]
In general, an if within an if is wrong. This idea should be expressed if (X AND Y). That eliminates an indentation level and makes the code more clear. I have no idea what you are trying to do here..
 if (grep { @input_B eq $_ } @input_array) 
   {
       if (grep { @input_A eq $_ } @input_array)
       {
        foreach my $inputKey (@input_array)

[download]
Update: You ask "I have three arrays such as below. What I want to do is if the element inside the arrays match, then it will do something."

Please explain what a "match" between these 3 array's means? I could not deduce that algorithm from your post.

In reply to Re: Matching elements inside two array by Marshall
in thread Matching elements inside two array by ameezys

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