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perl

my variable $x masks earlier declaration in same statement

I am confused on this error. This program takes user input 1 2 3 2 and displays the input in a specific order.

#!/usr/bin/perl -w
use strict;
use warnings;

print "Enter a number :";

my $num = <STDIN>;
chomp($num);

my @final = split(' ',$num);
my @count;
foreach my $x (@final){

 $count[my $x]++;

}
foreach my $x (@count){

    print my $x .$count[my $x];
}

My output: I get this error:

"my" variable $x masks earlier declaration in same statement at line 19

Expected output:

  • 1 1
  • 2 2
  • 3 1
Solution

  • You are using my a little bit too often.

    my is used to declare a variable, for the current scope (usually a block {...}).

    To use the variable, you don't need the my.

    So, in your first loop, do:

    $count[ $x ]++;

    In the second loop:

    print "$x: $count[ $x ]\n";

    See perldoc -f my and Private-Variables-via-my