URL

Anatomy of a URL

 
<protocol>://<hostname>:<port>/<path>?<query_params>

<protocol> required
  • http
  • https
  • ftp (probably don't need to know this one, also heaps more)

<hostname> required
  • localhost
  • google.com
  • tudelft.nl
  • cse1500.sendcroissants.me
  • really.long.and.nested.subdomains.co.uk

<port> optional
  • 80 (this is the default port when no port is specified)
  • 3000
  • 5000
  • ...and any other integer from 0 to 65535

<path> optional
  • login
  • calendar/january/31
  • ...it's a path. You know what a path is.

<query_params> optional

key=value pairs separated by &, comes after the ?. Usually used for sending data in a GET request since GET requests can't send content in the body.

  • username=kevin
  • username=kevin&token=fdfa8e7cc4b3
    • this is basically like sending this in the body: 
      {
    "username":"kevin",
    "token":"fdfa8e7cc4b3"
}

Examples

 
# Ordinary URL, note the <port> is missing, so it defaults to 80
https://google.com

# Pointing to computer's own address, note the port is specified as 3000
# Also note it has a query string with some data.
http://localhost:3000/register?username=kevin&password=yeet