1. What is JavaScript?

3 min readNov 2, 2020

JavaScript is a scripting and programming language for web. JavaScript can calculate, manipulate, and validate data. Suppose you have a car, the engine of this car is HTML, the color of this car is CSS, the JavaScript can be taken to the front of this car. Similarly, the web browser is HTML, the color of this web browser is CSS, something happened in this browser like:- validate content, calculate, manipulate, something happened on click all of this works the JavaScript can be taken to the front of this web browser.

2. What is JavaScript data types and structure types?

JavaScript has seven primitive data types:-

String.
Number.
Boolean.
Undefined.
Null.
Symbol.
BigInt.

JavaScript structure types:-

Object.
Array.
Function.

3. What is JavaScript String?

A JavaScript string store a series of characters like:- “JavaScript”, “100”, “This is JavaScript” etc.

4. What is JavaScript Number?

JavaScript has only one type of Number. All numbers except strings. Like:- 0,1,2,3,4,5,6,7,8,9 all numbers.

5. What is JavaScript Boolean?

A JavaScript Boolean express one or two values: true or false. Booleans are commonly used is conditional statements.

6. What is JavaScript Undefined?

Undefined is used as a falsy value in JavaScript. Undefined is the default value of a variable or that has not been assigned a specific value.

7. What is JavaScript Null?

Null is used as a falsy value in JavaScript. The null value indicates an empty value. It is essentially a placeholder that represents “nothing”. Also null value indicates an empty Object.

8. What is JavaScript Object?

Object means a description of something. In real life a car, a person, a bus, a train, a cycle etc. There are two things in the object like:- (a) property (b) associated values.