Lesson: Introduction to JavaScript – Data Types

Objective

By the end of this lesson, students will:

1. Understand the four main primitive data types in JavaScript.
2. Differentiate between strings, numbers, booleans, and null values.
3. Write and debug code using these data types effectively.

Introduction

In JavaScript, data types are the foundation of programming. They define the kind of values a variable can hold. JavaScript includes primitive data types, which are the simplest and most fundamental forms of data.

The four primary primitive data types in JavaScript are:

1. Strings
2. Numbers
3. Booleans
4. Null

Explanation of Primitive Data Types

1. Strings

Strings are used to represent text. They are sequences of characters wrapped in single (') or double (") quotes.

Example:

2. Numbers

Numbers represent numerical values, including both integers and decimals.

Example:

3. Booleans

Booleans represent logical states and can only be true or false.

Example:

4. Null

Null is a special keyword that represents the intentional absence of any value.

Example:

Code Example

The following code demonstrates all four primitive data types:

Exercise 1: Write Your Own Examples

Instructions

Write a program that:

1. Logs a string of your choice.
2. Logs a number of your choice.
3. Logs a boolean value.
4. Logs a null value.

Solution

Exercise 2: Debugging Activity

Here’s a buggy code snippet. Identify and fix the errors:

Solution

Exercise 3: Advanced Challenge

1. Create variables for each primitive data type and assign them values.
2. Log the type of each variable using the typeof operator.

Solution

Quiz

Multiple Choice Questions

1. Which of the following is a string?
   • a) "Hello"
   • b) 42
   • c) true
   • d) null
     Answer: a)
2. What does null represent in JavaScript?
   • a) A string with no characters.
   • b) A value that equals zero.
   • c) The intentional absence of any value.
   • d) A boolean value.
     Answer: c)
3. What will typeof null return in JavaScript?
   • a) null
   • b) undefined
   • c) object
   • d) boolean
     Answer: c)

Coding Quiz

Write a program to:

1. Declare a variable for each primitive data type.
2. Log each variable and its type using typeof.

SOLUTION

Recap

• Strings are sequences of characters wrapped in quotes.
• Numbers represent numerical values.
• Booleans are logical values (true or false).
• Null represents the absence of value.

Data Types In JavaScript (Primitive & Reference Type) | JavaScript Tutorial  (VIDEO)

Related Videos:

Related Posts:

Using CSS classes and the class attribute

Learn about Python Conditions

Storing and Modifying Information (CRUD)

Coding with JavaScript

The Python Standard Library Ver 3.13.1

Why is Java not a pure object oriented language?

Introduction to JavaScript – Create a Variable: let

Learn about JavaScript ELSE STATEMENTS

What is the default value for Boolean variable in VB.NET?

What is Python?