JS Web Development

Question 1

What is JSON?

Answer 1

a universally readable data interchange format that follows JavaScript object syntax

Question 2

What are serialization and deserialization?

Answer 2

serialization: converting an object into a string
deserialization: turning the string back into the same object

Question 3

Why are serialization and deserialization useful?

Answer 3

useful because they let you send data in a universally readable format

Question 4

How do you serialize a data structure into a JSON string using JavaScript?

Answer 4

JSON.stringify()

Question 5

How do you deserialize a JSON string into a data structure using JavaScript?

Answer 5

JSON.parse()

Question 6

What is a client?

Answer 6

The application that is requesting a service or function

Question 7

What is a server?

Answer 7

The application that is providing a service or resource

Question 8

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

Answer 8

GET

Question 9

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

Answer 9

1. The HTTP method (ex. GET, POST, DELETE, PUT, etc)
2. Request target (a url including any query string)
3. The HTTP version

Question 10

What three things are on the start-line (aka status line) of an HTTP response message?

Answer 10

1. The protocol version
2. A status code/response code indicating success or failure of request (ex 200, 404)
3. A status text; a brief human-readable description of status code (ex. ‘Not Found’, ‘OK’)

Question 11

What are HTTP headers?

Answer 11

HTTP headers let the client or server pass additional information with an HTTP request or response.

Question 12

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

Answer 12

No, the message body is optional

Question 13

What is AJAX?

Answer 13

Anything that makes a request to an outside source and then updates a web page after it has been loaded.

Ajax allows you to request data from a server and load it without having to refresh page

Question 14

What does the AJAX acronym stand for?

Answer 14

Asynchronous Javascript and XML

This is what the letters literally stand for; but the term AJAX as it’s used today does not specifically mean this.

Question 15

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

Answer 15

The XMLHttpRequest object

Question 16

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

Answer 16

The load event

Question 17

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

Answer 17

Both DOM elements and the XMLHttpRequest object inherit this method through prototypal inheritance from the EventTarget object