Why doesn't decodeURI(“a+b”) == “a b”?

Question

I\'m trying to encode URLs in Ruby and decode them with Javascript. However, the plus character is giving me weird behavior.

In Ruby:

[Dev]> CGI.e         


        

Answer 1

From MDC decodeURI:

Does not decode escape sequences that could not have been introduced by encodeURI.

From MDC encodeURI:

Note that encodeURI by itself cannot form proper HTTP GET and POST requests, such as for XMLHTTPRequests, because "&", "+", and "=" are not encoded