Question

I have tried to make a regex I use with php evolve, but by adding an additional one-character group, the regex no longer finds any matches.

Previous version was:

$pattern = '{\{[0-9]+[a-z][0,1][0,1]\}}';

matching strings like {010c10} or {009c10}.

I then decided to make the strings to be matched evolve by adding a [0,1] character, adapting the regex as follows:

$pattern = '{\{[0-9]+[a-z][0,1][0,1][0,1]\}}';

However, the regex now no longer matches strings like {010c100}
, and I really cannot see why.

Answer 1

// match short versions, such as {010c10}
$pattern = '/\{\d+[a-z][0,1]{2}\}/'; 

// match long versions, such as {010c100}
$pattern = '/\{\d+[a-z][0,1]{3}\}/'; 

// match short and/or long versions
$pattern = '/\{\d+[a-z][0,1]{2,3}\}/';