How can the order of strings in a regular expression impact matching in PHP?

The order of strings in a regular expression can impact matching in PHP because the regex engine will attempt to match the patterns in the order they are specified. If a more general pattern comes before a more specific one, the general pattern may match first and prevent the specific pattern from being matched. To solve this issue, you can reorder the strings in the regular expression so that the more specific patterns come before the more general ones. 

$pattern = '/specific_pattern|general_pattern/';
$string = 'input_string';

if (preg_match($pattern, $string)) {
    echo 'Match found!';
} else {
    echo 'No match found';
}

Keywords

Regular expression matching order strings PHP

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