Question

Is anyone aware of a way to remove redundant variables from a query string.

For example, reducing the below URL from this:

youtube.com/watch?v=123&feature=g-all&something=lalala

To the following:

youtube.com/watch?v=123

Alternatively, how could you compare two URLs with a different query string to check if they are the same page?

Answer 1

php has built in functions for this; parse_url() and parse_str()

parse_str( 'watch?v=123&feature=g-all&something=lalala' );

// returns

array(3) {
  ["v"]=>
  string(3) "123"
  ["feature"]=>
  string(5) "g-all"
  ["something"]=>
  string(6) "lalala"
}

So, you can use both functions to extract the parameters you want without having to explode and guess the position of the parameters.

$url = parse_url( "youtube.com/watch?v=123&feature=g-all&something=lalala" );

parse_str( $url['query'], $query );

echo 'youtube.com/?v=' . $query["v"];  // youtube.com/?v=123

This should be better than exploding or even using regex.