http://www.perlmonks.org?node_id=542260


in reply to Bad return value from a block with variable localization

It also helps to actually "return 1;" instead of just "1;" In general use the short form only when you are really at the end of a subroutine. do blocks are not really subroutines.
#!/usr/bin/perl use strict; use warnings; # let's just remove the else sub foo { if (@_) { return do { my $dummy; return 1; }; } 0; } sub bar { if (@_) { return do { my $dummy; return 1; }; } else { 0; } } print foo() . ' ' . foo('baz') . "\n"; # 1 0 print bar() . ' ' . bar('baz') . "\n"; # also 1 0
Update:
I noticed that the above script is bad style for a direct return from the subroutine. You should use eval instead of do. See the example below.
#!/usr/bin/perl use strict; use warnings; # let's just remove the else sub foo { if (@_) { return 10 + do { my $dummy; return 1; }; } 0; } sub bar { if (@_) { return 10 + eval { my $dummy; return 1; }; } 0; } print foo() . ' ' . foo('baz') . "\n"; # 1 0 print bar() . ' ' . bar('baz') . "\n"; # 11 0