JSON

Question 1

What is JSON?

Answer 1

o JavaScript Object Notation
o Formatting system to make an object into a string and vice versa
o Format to create data that can be saved in the long term and to also be able to easily send/receive data

Question 2

What are serialization and deserialization?

Answer 2

Serialization – process of turning an object in memory into stream of bytes

Deserialization – Turning byes into an object in memory

Question 3

Why are serialization and deserialization useful?

Answer 3

It makes it possible to send/receive data

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

How to you store data in localStorage?

Answer 6

localStorage.setItem(‘key’, ‘value’)

Question 7

How do you retrieve data from localStorage?

Answer 7

localStorage.getItem(‘keyname’)

Question 8

What data type can localStorage save in the browser?

Answer 8

String

Question 9

When does the ‘beforeunload’ event fire on the window object?

Answer 9

Before the page unloads (when window is about to be closed, before closing the tab, etc)