How can I use str_replace method for replacing a specified portion(between two substrings). For example,
string1="www.example.com?test=abc&var=55";
string2="www.example.com?test=xyz&var=55";
I want to replace the string between '?------&' in the url with ?res=pqrs&. Are there any other methods available?
You could use preg_replace to do that, but is that really what you are trying to do here?
$str = preg_replace('/\?.*?&/', '?', $input);
If the question is really "I want to remove the test parameter from the query string" then a more robust alternative would be to use some string manipulation, parse_url or parse_str and http_build_query instead:
list($path, $query) = explode('?', $input, 2);
parse_str($query, $parameters);
unset($parameters['test']);
$str = $path.'?'.http_build_query($parameters);
Since you're working with URL's, you can decompose the URL first, remove what you need and put it back together like so:
$string1="www.example.com?test=abc&var=55";
// fetch the part after ?
$qs = parse_url($string1, PHP_URL_QUERY);
// turn it into an associative array
parse_str($qs, $a);
unset($a['test']); // remove test=abc
$a['res'] = 'pqrs'; // add res=pqrs
// put it back together
echo substr($string1, 0, -strlen($qs)) . http_build_query($a);
There's probably a few gotchas here and there; you may want to cater for edge cases, etc. but this works on the given inputs.
Dirty version:
$start = strpos($string1, '?');
$end = strpos($string1, '&');
echo substr($string1, 0, $start+1) . '--replace--' . substr($string1, $end);
Better:
preg_replace('/\?[^&]+&/', '?--replace--&', $string1);
Depending on whether you want to keep the ? and &, the regex can be mofidied, but it would be quicker to repeat them in the replaced string.
