How to encode a query string so that it is the value of another query string in javascript?

Solution 1:

encodeURIComponent will work. (You may or may not want the leading ‘?’, depending on what the script is expecting.)

var c= 'd e'
var query= '?a=b&c='+encodeURIComponent(c);
var uri= 'http://www.example.com/script?query='+encodeURIComponent(query);
window.location= uri;

Takes me to:

http://www.example.com/script?query=%3Fa%3Db%26c%3Dd%2520e

When you hover over that it may appear once-decoded in the browser's status bar, but you will end up in the right place.

escape/unescape() is the wrong thing for encoding query parameters, it gets Unicode characters and pluses wrong. There is almost never a case where escape() is what you really need.

Solution 2:

Native escape method does that. but also you can create a custom encoder like:

function encodeUriSegment(val) {
  return encodeUriQuery(val, true).
             replace(/%26/gi, '&').
             replace(/%3D/gi, '=').
             replace(/%2B/gi, '+');
}

this will replace keys used in query strings. further more you can apply it to any other custom encodings by adding needed key-values pairs.