#!/usr/bin/perl

 $key = 1;
 $key1 = "test";
 $key2 = "";
 $key3 = 0;


if (($key ne "") && ($key != 0)){

                print "\n$key\n";

}


OUTPUT :

Correct For $key  : 1
Incorrect For $key1 : 
Correct For $key2 : 
Incorrect For $key3 :