JavaScript: Primitive Data Types

Question 1

What are the five main primitive data types?

Answer 1

Primitive data types include (1) undefined, (2) string, (3) number, (4) boolean and (5) null

Question 2

Undefined

Answer 2

Undefined variables haven’t been assigned values yet.

let myUndefined;

Question 3

String

Answer 3

A string is a series of characters and is surrounded by quotes .

const myStringWelcome = “Hello World”;
const myStringPassword = “865Password!2020”;

Question 4

Number

Answer 4

A number can be either an integer or a decimal.

const myNumberInt = 100;
const myNumberDecimal = 100.100;

Question 5

Booleans

Answer 5

Booleans have two values: true or false.

const isMyBooleanTrue = true;
const isMyBooleanFalse = false;

Question 6

Null

Answer 6

Null is both a value and type. It represents the concept of nothing. This differs from undefined, which is an unknown value. Null is known to be nothing.

const myNull = null;

Question 7

How do you check the type of data?

Answer 7

To check the type of data, use typeof followed by the name of the variable.

console.log(typeof myUndefined);