HTTP

Question 1

What is a client?

Answer 1

a service requester of a server

Question 2

What is a server?

Answer 2

a service provider, providing web pages or files to clients

Question 3

Which HTTP method does a browser issue to a web server when you visit a URL?

Answer 3

GET request

Question 4

What three things are on the start-line of an HTTP request message?

Answer 4

1.HTTP method (GET, POST), 2.Request target (URL, path), 3.HTTP version protocol
examples: POST / HTTP/1.1
GET /background.png HTTP/1.0

Question 5

What three things are on the start-line of an HTTP response message?

Answer 5

1. Protocol version (HTTP/1.1), 2.Status code (200, 404, 302), 3.Status text
   example: HTTP/1.1 404 Not Found.

Question 6

What are HTTP headers?

Answer 6

a header is a string followed by a colon with a value, which allows the client and server to pass additional information with an HTTP request or response

Question 7

Is a body required for a valid HTTP request or response message?

Answer 7

no, it’s optional

Question 8

What is AJAX?

Answer 8

the practice of building complex, dynamic webpages using XMLHttpRequest

Question 9

What does the AJAX acronym stand for?

Answer 9

Asynchronous JavaScript and XML

Question 10

Which object is built into the browser for making HTTP requests in JavaScript?

Answer 10

the XMLHttpRequest object

Question 11

What event is fired by XMLHttpRequest objects when they are finished loading the data from the server?

Answer 11

the ‘load’ event

Question 12

An XMLHttpRequest object has an addEventListener() method just like DOM elements. How is it possible that they both share this functionality?

Answer 12

both are chained on the EventTarget prototype