Test if string is URL encoded in PHP

Question

How can I test if a string is URL encoded?

Which of the following approaches is better?

• Search the string for characters which would be encoded, which

Answer 1

In my case I wanted to check if a complete URL is encoded, so I already knew that the URL must contain the string https://, and what I did was to check if the string had the encoded version of https:// in it (https%3A%2F%2F) and if it didn't, then I knew it was not encoded:

//make sure $completeUrl is encoded
if (strpos($completeUrl, urlencode('https://')) === false) {
    // not encoded, need to encode it
    $completeUrl = urlencode($completeUrl);
}

in theory this solution can be used with any string other than complete URLs, as long as you know part of the string (https:// in this example) will always exists in what you are trying to check.