Hello Perl_Programmer1992, and welcome to the Monastery!

“The preceding character” means the single, immediately preceding character, in this case m. But the character before that — another m — is not present in the string held by the variable $what, so there is no match. If you change the regex to /com?a/, it matches.

Other metacharacters: + matches one or more of the preceding character; * matches zero or more of the preceding character; . (dot) matches any one (single) character (except a newline). Parentheses () are used for capturing: reading from left to right, the captured strings are available in the special variables $1, $2, etc. See “Metacharacters” under perlre#The-Basics.

Hope that helps,

Athanasius <°(((>< contra mundum Iustus alius egestas vitae, eros Piratica,

In reply to Re: Conceptual doubt in metacharacters : Beginner in perl by Athanasius
in thread Conceptual doubt in metacharacters : Beginner in perl by Perl_Programmer1992

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