Changing the value of a single variable in querystring

Question

I am assigned the URL of the page, for example, 'http://abc.com/test.php?a=1&b=2&c=3' . Now I was told to change the value of b to 5 so that it becomes 'http://abc.com/test.php?a=1&b=5&c=3' .

ie change from http://abc.com/test.php?a=1&b=2&c=3 to http://abc.com/test.php?a=1&b=5&c=3

Note: the variable b can refer to any name here.

Answer 1

Using

• parse_url() to retrieve a query string from a URL

• parse_str() to split the query string into an array

• array_merge() to add a new array "b" => 5

• http_build_query() to reassemble the query string

• The remaining parts from the first step (protocol, host, path ...) for reassembling the full URL or - if you have the HTTP pecl extension - a http_build_url() with HTTP_URL_JOIN_QUERY will facilitate most of the work.