I tried using Ruby's url_encode (doc here.)
It encodes http://www.google.com as http%3A%2F%2Fwww.google.com. But it turns out that I cannot open the latter via a browser. If so, what's the use of this function? What is it useful for, when the URL that it encodes can't even be opened?
A typical use is the HTTP GET method, in where you need a query String.
Query String 1:
valudA=john&valueB=john2
Actual value server get:
valueA : "john"
valueB : "john2"
url_encode is used to make the key-value pair enable to store the string which includes some non-ASCII encoded character such as space and special character.
Suppose the valueB will store my name, code 4 j, you need to encode it because there are some spaces.
url_encode("code 4 j")
code%204%20j
Query string 2:
valueA=john&valueB=code%204%20j
Actual value server get:
code 4 j with spaces? What's wrong with that?
You can use url_encode to encode for example the keys/values of a GET request.
Here is an example of what a SO search query URL looks after encoding:
https://stackoverflow.com/questions/tagged/c%23+or+.net+or+asp.net
As you can see, url encoding appears to be applied only on the last part of the URL, after the last slash.
In general you cannot use url_encode on your entire URL or you will also encode the special characters in a normal URL like the :// in your example.
You can check a tutorial that explains how it works here: http://www.permadi.com/tutorial/urlEncoding/
