How can I make the Perl regex part optional?

Question

I want a match

 my @array = ( 'Tree' , 'JoeTree');

    foreach (@array ) {
      if ( $_ =~ /^(Joe)Tree/gi) {
        print "matched $_";
      }
    }

This only matches JoeTree. Does this not match the tree?

Answer 1

Try:

if (/^(?:Joe)?Tree/gi)

• We have added a part Joe.
• You can also change (..)to (?:...)because you are just grouping.
• Also, the part $_ =~is redundant, since by default we check$_

Answer 2

You missed ?:/^(Joe)?Tree/gi