How can UTF-8 encoding be optimized in PHP scripts to avoid unnecessary encoding?

When working with UTF-8 encoding in PHP scripts, it is important to ensure that unnecessary encoding is avoided to optimize performance. One way to achieve this is by checking if the string is already UTF-8 encoded before applying any encoding functions. This can help prevent double encoding and unnecessary processing.

// Check if the string is already UTF-8 encoded before applying encoding functions
function utf8_encode_optimized($string) {
    if (mb_detect_encoding($string, 'UTF-8', true) === 'UTF-8') {
        return $string;
    } else {
        return utf8_encode($string);
    }
}

// Example usage
$string = "UTF-8 encoded string";
$optimized_string = utf8_encode_optimized($string);
echo $optimized_string;