JavaScript Expressions and Statements (Beginner Guide)

Javascript Feb 5, 2023
JavaScript Expressions and Statements (Beginner Guide)

Welcome to the world of JavaScript programming! If you're new to the world of web development, you're in the right place. This beginner's guide will help you understand the basics of JavaScript expressions and statements. Using these basic building blocks, you'll be able to create dynamic and interactive web applications.

What are JavaScript Expressions?

A JavaScript expression is a combination of value variables and operators that computes a value. The result of an expression can be assigned to a variable or used as an argument in a function. Expressions can also be used in conditional statements, such as "if-else" to control The flow of your program.

For example consider the expression “2 + 3”. When this expression is evaluated, it returns the value 5. Another example is the expression "a * b", where "a" and "b" are variables storing values.

How to use JavaScript Expressions in a Web App

JavaScript expressions are used in many different ways to create dynamic web applications. For example, you can use expressions to calculate the total cost of items in an online shopping cart or to generate random numbers for a game.

To use expressions in web applications, you can include them in script tags in HTML code.

For example:

You can create a simple calculation to determine the total cost of items in the cart:

var price = 5;
var quantity = 10;
var total = price * quantity;
document.write("The total cost is $" + total);

What are JavaScript Statements?

JavaScript statements are individual instructions executed by the browser. Unlike expression statements do not return a value. Statements are used to perform operations such as declaring variables that define functions and control program flow.

For example:

  1. The statement “var x = 5” declares a variable “x” and assigns it the value 5.
  2. the statement “if (x > 5) { … }”, which checks if the value of “x” is greater than 5 and executes the code within the curly braces if it is.

Why Should You Use JavaScript Expressions and Statements?

JavaScript expressions and statements are the basic building blocks for creating dynamic and interactive web applications. Using these basic concepts, you can add functionality and interactivity to your website, making it more attractive and user-friendly.


Expressions and statements are easy to understand and use, and are the foundation of JavaScript programming. By mastering these fundamentals, you'll be able to create stunning web applications that bring your ideas to life.