How can the range [a-z-ß] in a regular expression impact the validation of input fields in PHP?

When using the range [a-z-ß] in a regular expression for input validation in PHP, it may not correctly match the special character "ß" as it falls outside the ASCII range of a-z. To include the "ß" character in the validation, you can use the Unicode representation or specify the character directly in the regular expression pattern. 

// Example of input validation using a regular expression with the range [a-z-ß]
$input = "abcdeß";
if (preg_match('/^[a-zß]+$/', $input)) {
    echo "Input is valid.";
} else {
    echo "Input is invalid.";
}

Keywords

regular expression validation input fields range PHP

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