How can error handling be implemented in PHP to display custom error messages instead of PHP error messages?

To display custom error messages instead of PHP error messages, you can use the `set_error_handler()` function in PHP to define a custom error handler. This custom error handler can then be used to catch PHP errors and exceptions, and display custom error messages or perform specific actions based on the error type.

// Custom error handler function
function customErrorHandler($errno, $errstr, $errfile, $errline) {
    echo "Custom Error: [$errno] $errstr\n";
    echo "Error on line $errline in $errfile\n";
}

// Set custom error handler
set_error_handler("customErrorHandler");

// Trigger an error to test
echo $undefinedVariable;