How to convert a HTTP link to HTTPS with PHP

I recently had to import some HTTP URLs that needed converting to HTTPS; Here’s how I did it. This is better than just running a str_replace because it only replaces http:// if it appears at the beginning of the string.

$string = 'http://www.texelate.co.uk';
$prefix = 'http://';
		
// Jupix sends links as http:// so change to https://
if (substr($string, 0, mb_strlen($prefix)) === $prefix) {
			
    $string = 'https://' . mb_substr($string, mb_strlen($prefix));
			
}

echo $string; // https://www.texelate.co.uk