Variables & Constants in JavaScript Simplified Revision Notes for A-Level OCR Computer Science

Revision notes with simplified explanations to understand Variables & Constants in JavaScript quickly and effectively.

Learn about Web Technologies for your A-Level Computer Science Exam. This Revision Note includes a summary of Web Technologies for easy recall in your Computer Science exam

291+ students studying

Variables & Constants in JavaScript

Overview

Variables in JavaScript store data values that can be used and modified, while constants are fixed values that cannot be changed once set. Variables and constants are fundamental to storing and processing data in JavaScript.

Key Concepts

Declaring Variables: Use let or var to declare variables, and const to declare constants.
Data Types: JavaScript supports types like numbers, strings, and booleans.

lightbulbExample

Example:

let age = 25;
const pi = 3.14159;

infoNote

Common Mistakes

Reassigning a constant: Constants (const) cannot be reassigned after their initial assignment.
Using var instead of let or const: var has function scope, which can lead to unexpected results.

infoNote

Key Takeaways

Use let for variables that change and const for constants.
Understand the basic data types and when to use each one.

500K+ Students Use These Powerful Tools to Master Variables & Constants in JavaScript For their A-Level Exams.

Enhance your understanding with flashcards, quizzes, and exams—designed to help you grasp key concepts, reinforce learning, and master any topic with confidence!

160 flashcards

Flashcards on Variables & Constants in JavaScript

Revise key concepts with interactive flashcards.

Try Computer Science Flashcards

16 quizzes

Quizzes on Variables & Constants in JavaScript

Test your knowledge with fun and engaging quizzes.

Try Computer Science Quizzes

29 questions

Exam questions on Variables & Constants in JavaScript

Boost your confidence with real exam questions.

Try Computer Science Questions