JSON

Question 1

What is JSON?

Answer 1

JavaScript Object Notation. It’s a standard text-based format for representing structured data based on JavaScript object syntax. This is commonly used for transmitting data in web applications.

Question 2

What are serialization and deserialization?

Answer 2

Serialization is the process of converting an object in memory into a byte stream so that it can be stored on disk or transferred over the network. Deserialization is the inverse process of converting a stream of bytes into an object in memory.

Question 3

Why are serialization and deserialization useful?

Answer 3

To save the state of an object in order to be able to recreate it when needed.

Question 4

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

Answer 4

Using the JSON.stringify() method.

Question 5

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

Answer 5

Using the JSON.parse() method.

Question 6

How do you store data in localStorage?

Answer 6

Using the setItem() method.

Question 7

How do you retrieve data from localStorage?

Answer 7

Using the getItem() method.

Question 8

What data type can localStorage save in the browser?

Answer 8

Only strings.

Question 9

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

Answer 9

The event is fired when the window, the document, and its resources are about to be unloaded, like refresh or close the window.