CODEWITHSUNDEEP
perl
constantlearner
constantlearner

Reputation: 5247

Perl error in grepping array

I have written a sub procedure in perl to check whether if my string array contains a particular value.

sub check_if_entity_exists() {

    my $entity      = shift;
    my @entityarray = @_;

    print "my entity to be checked $entity  \n";
    print "entity array before change  @entityarray : \n";

    join(" ", map { s/^\s*|\s*$//g; $_ } @entityarray);

    print " array after change @entityarray \n";

    my $status = "FALSE";

    if (grep { $_ eq $entity } @entityarray) {
        $status = "TRUE";
        return $status;
    }
    else {
        return $status;
    }
}

In the above code @entityarray = xyz.com $entity = xyz.com Since entity is there in entity array i expect to set to true but flow is going to false

Output log: my entity to be checked xyz.com entity array before change xyz.com : array after change xyz.com

Upvotes: 0

Views: 103

Answers (1)

Borodin
Borodin

Reputation: 126762

You have an empty prototype for your check_if_entity_exists subroutine. That insists that there must be no parameters to this subroutine, which is wrong. You should never use prototypes in Perl - they work differently from prototyps in other langauges and are meant for something very specific.

You are also using map in void context, and join generates a string that is immediately discarded. You should always have

use strict;
use warnings;

at the top of all your programs, which would have told you

Useless use of join in void context

And you should write the map loop as

for (@entityarray) {
  s/^\s+//;
  s/\s+\z//;
}

Other than that, your code does what it should for me. If I call it like this

my @entityarray = ('    xyz.com    ');
my $entity = 'xyz.com';

print check_if_entity_exists($entity, @entityarray);

output

my entity to be checked xyz.com  
entity array before change      xyz.com     : 
 array after change xyz.com 
TRUE

It would be better to write this using the first function from List::Util, like this

use List::Util 'first';

sub check_if_entity_exists {
  my $entity = shift;
  defined(first { /^\s*\Q$entity\E\s*$/ } @_) ? 'TRUE' : 'FALSE';
}

Upvotes: 3

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