Regex to capture everything before first optional string

Question

I want to capture a pattern upto but not including the first instance of an optional other pattern with preg_match, eg:

ABCDEFGwTW$%                                  


        

Answer 1

Using preg_match() with a pattern that uses lazy matching and a lookahead is going to take more steps than just using preg_replace() with greedy matching (and no lookarounds) and simply replacing the optional match with an empty string. If the needle doesn't exist, then nothing is changed in the string. Super easy.

Code: (Demo)

$strings = [
    'ABCDEFGwTW$%',
    '@Q%HG@H%hg afdgwsa g   weg#D DEFG',
    '@Q%HDEFG@H%hg afdgwsa g   weg#D DEFG',
    'No needle in the haystack',
];

var_export(preg_replace('/EFG.*/', '', $strings));

Output:

array (
  0 => 'ABCD',
  1 => '@Q%HG@H%hg afdgwsa g   weg#D D',
  2 => '@Q%HD',
  3 => 'No needle in the haystack',
)