Question

I have a hash named %coins.
I am to trying to modify the value of the hash if the key of the hash matches with some string.
I tried the following code, but couldn’t succeed. It is creating new key instead of modifying the existing key’s value.

Please help

#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my %coins;
%coins = ( "abc" , 1,
          "mno pqr" , 2,
          "xyz",  3 );

print Dumper \%coins;

if(grep {/mno/} keys %coins)
{
    print"matched \n";
    $coins{$_} = s/$coins{$_}/new_val/g;
}

print Dumper \%coins;

Answer 1

For starters, change

if(grep {/mno/} keys %coins)
{
    ...
}

to

for(grep {/mno/} keys %coins)
{
    ...
}

As for the value, you want to

( my $new_val = $_ ) =~ s/mno/new_value/g;
$coins{$_} = $new_val;

or

$coins{$_} = $_ =~ s/mno/new_value/gr;    # Perl 5.14+