How can I replace the "+" plus sign with its corresponding url encoding of "%2B"?

I'm having some trouble replacing the "+" sign with its urlencoded string of "%2B". How can I do this?

This is what I've tried:

Text Entered into text box:

plus(+)

I then urlencode the string:

$string = urlencode($string);

String now looks like:

plus%28+%29

I want to have the "+" urlencoded, or else when I urldecode() the data to display in browser I end up with:

plus( ) 

because urldecode() interprets the "+" to be a space.

I tried using php's str_replac开发者_如何学Ce() but I keep getting a "NULL" returned as the value for "$new_string":

$new_string = str_replace('+', '%2B', $string);

Any ideas?

Thanks in advance!

That is strange. When I use urlencode on plus(+) I get plus%28%2B%29. Make sure you're using it correctly.

You might also try rawurlencode. It will encode spaces as %20 instead of +.

That helped me:

function _rawurlencode($string) {
    $string = rawurlencode(str_replace('+','%2B',$string));
    return $string;
}