Search and replace specific query string parameter value in javascript

Question

I have a string which is something like this :

a_href= \"www.google.com/test_ref=abc\";

I need to search for test_ref=abc in thisabove stri

Answer 1

I know this is a bit dirty code but I've achieved what I was looking for. It replaces the given query string or adds new one if it doesn't exist yet.

function updateUrlParameter(url, param, value) {

    var index = url.indexOf("?");

    if (index > 0) {

        var u = url.substring(index + 1).split("&");

        var params = new Array(u.length);

        var p;
        var found = false;

        for (var i = 0; i < u.length; i++) {
            params[i] = u[i].split("=");
            if (params[i][0] === param) {
                params[i][1] = value;
                found = true;
            }
        }

        if (!found) {
            params.push(new Array(2));
            params[params.length - 1][0] = param;
            params[params.length - 1][1] = value;
        }

        var res = url.substring(0, index + 1) + params[0][0] + "=" + params[0][1];
        for (var i = 1; i < params.length; i++) {
            res += "&" + params[i][0] + "=" + params[i][1];
        }
        return res;

    } else {
        return url + "?" + param + "=" + value;
    }

}

It will work when given regular URL addresses like:

updateUrlParameter('https://www.example.com/some.aspx?mid=1&id=2','id','5');
updateUrlParameter('https://www.example.com/?mid=1&id=2','id','5');
updateUrlParameter('https://www.example.com/some.aspx','id','5');

Please note It will NOT work only if any of the query string parameter name or value contains "=" and/or "&" chars. It will work just fine behind that.