What is the significance of using strtolower() function in PHP for the given error message?

The significance of using strtolower() function in PHP for the given error message is to ensure that the comparison between strings is case-insensitive. This is important because the error message might be written in different cases (e.g., uppercase, lowercase, or mixed case), and using strtolower() helps normalize the case for accurate comparisons.

$error_message = "Invalid username or password";
$user_input = "invalid username or password";

if(strtolower($user_input) === strtolower($error_message)) {
    echo "Error message matches user input.";
} else {
    echo "Error message does not match user input.";
}