What is the maximum length in a RegExp Range [] in PHP?

In PHP, the maximum length in a RegExp Range [] is 65535 characters. If you need to match a longer range, you can break it down into multiple ranges or use a different approach such as using a loop to check each character individually. 

// Example of breaking down a long range into multiple ranges
$pattern = '/[a-z0-9]{0,65535}[a-z0-9]{0,65535}/';

// Example of using a loop to check each character individually
$string = 'abcdefghijklmnopqrstuvwxyz0123456789';
$valid = true;
for ($i = 0; $i < strlen($string); $i++) {
    if (!preg_match('/[a-z0-9]/', $string[$i])) {
        $valid = false;
        break;
    }
}
if ($valid) {
    echo 'String contains only lowercase letters and numbers.';
} else {
    echo 'String contains invalid characters.';
}

Keywords

PHP RegExp Range Maximum length Limit

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