JavaScript Data Types

Data types in JavaScript are used to define the type of data that can be stored in a variable or constant. JavaScript has several built-in data types, each serving a specific purpose. Let's explore the most common ones.

Why Data Types are Used

Data types are important in JavaScript for several reasons:

They define how data is stored and processed. They help prevent unexpected type-related errors. They enable the interpreter to allocate memory and optimize code execution.

Number

The Number data type represents both integer and floating-point numbers. It is used for mathematical operations, such as addition, subtraction, multiplication, and division.

Example:

1let age = 25;
2let price = 19.99;

String

The String data type is used to store text data. Strings are enclosed in single or double quotes or back tick "`".

Example:

1let name = "John";
2let message = "Hello, World!";

Boolean

The Boolean data type has two values: true and false. It is used for making decisions in your code, such as in if statements and loops.

Example:

1let isTall = true;
2let isOpen = false;

4. Null

The Null data type represents the intentional absence of value.

Example:

1let emptyValue = null;

5. Undefined

The Undefined data type represents a variable that has been declared but not assigned a value.

Example:

1let notDefined;

Other Data Types

There are other data types on javascript like array, object, classes. We will talk about this on our future lesson.