HTTP/JavaScript AJAX

Question 1

What is a client?

Answer 1

anyone that requests service from a server

Question 2

What is a server?

Answer 2

it provides various functionalities, data, and resources to the client

Question 3

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

Answer 3

GET

Question 4

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

Answer 4

an http method, a requested target (usually a url), the http version

Question 5

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

Answer 5

the protocol version (usually HTTP/1.1), the status code, a status text

Question 6

What are HTTP headers?

Answer 6

it lets the client pass additional information with an HTTP request or response

Question 7

Where would you go if you wanted to learn more about a specific HTTP Header?

Answer 7

mdn

Question 8

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

Answer 8

no

Question 9

What is AJAX?

Answer 9

it allows you to update a part of the page by accessing the data for only that part so that it changes without having to reload the page entirely

Question 10

What does the AJAX acronym stand for?

Answer 10

Asynchronous JavaScript and XML

Question 11

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

Answer 11

XMLHttpRequest

Question 12

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

Answer 12

the load event is fired

Question 13

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

Answer 13

prototypal inheritance