Can I break out of a subroutine before the end?

[Anonymous Monk]

You can break out of a subroutine by using the return keyword :

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

sub test {
  my ($param) = @_;

  if ($param =~ /e/) {
    print "e found.\n";
    return;
  };
  print "No e found.\n";
};

&test( "test" );
&test( "toast" );

Note that jumping out of the middle of a subroutine is considered bad style by some people who do believe in the statement that every routine should have one entrypoint and one exit.

[AcidHawk]

To simplify the given example and keep to the "one entry point one exit point to and from a subroutine" style, I would only add an else to the subroutines if statement Check the following:

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

sub test {
  my ($param) = @_;

  if ($param =~ /e/) {
    print "e found.\n";
  }
  else {
    print "No e found.\n";
  }
};

&test( "test" );
&test( "toast" );

I have also tried the following in case there are more than two options ie (more than true or false). I have only one entry point in a subroutine and one exit from that routine. It does mean though that I have to test the return value of the subroutine. Using the same example as above I could expand the tests (if statements) and the value that is returned, and then test these values later. E.g.

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

sub test {
  my ($param) = @_;
  my $rc = 0;

  if ($param =~ /e/) {
    $rc = 1;
  }
  elsif ($param =~ /a/) {
    $rc = 2;
  }
  return($rc);
};

my @tsts = qw/ test toast kitty /;

foreach my $word (@tsts) {
        my $ret_val = &test($word);
    if ($ret_val == 1) {
        print "E found\n";
    }
    elsif ($ret_val == 2) {
        print "A found\n";
    }
    else {
        print "A or E NOT found\n";
    }
}