Running JavaScript in browser console - Mini Project: Build & Apply

Running JavaScript in Browser Console

📖 Scenario: You want to quickly test some JavaScript code in your web browser without creating a file. The browser console lets you type and run JavaScript commands directly on any webpage.

🎯 Goal: You will learn how to open the browser console, create a simple variable, write a small function, and print output to the console.

📋 What You'll Learn

Open the browser console using keyboard shortcuts

Create a variable called greeting with the value 'Hello, world!'

Create a function called sayHello that returns the greeting variable

Use console.log to print the result of calling sayHello()

💡 Why This Matters

🌍 Real World

Developers often use the browser console to quickly test code snippets or debug web pages without creating files.

💼 Career

Knowing how to use the browser console is essential for web developers and testers to inspect and interact with live web pages.

1

Open the browser console and create a variable

Open your browser console. Then create a variable called greeting and set it to the string 'Hello, world!'.

Javascript

// Your code here
// Create a variable called greeting and set it to 'Hello, world!'

Need a hint?

Use const greeting = 'Hello, world!'; to create the variable.

2

Create a function that returns the greeting

Create a function called sayHello that returns the variable greeting.

Javascript

const greeting = 'Hello, world!';

// Your code here
// Create a function sayHello that returns greeting

Need a hint?

Define the function with function sayHello() { return greeting; }.

3

Print the greeting using console.log

Use console.log to print the result of calling sayHello().

Javascript

const greeting = 'Hello, world!';

function sayHello() {
    return greeting;
}

// Your code here
// Print the result of sayHello() using console.log

Need a hint?

Use console.log(sayHello()); to print the greeting.

4

Run all code together in the browser console

Copy all the code below and paste it into your browser console. Then press Enter to run it and see the output.

Code:
const greeting = 'Hello, world!';
function sayHello() {
return greeting;
}
console.log(sayHello());

Javascript

const greeting = 'Hello, world!';

function sayHello() {
    return greeting;
}

console.log(sayHello());

// Paste all code into the browser console and run

Need a hint?

Open the browser console (F12 or Ctrl+Shift+I), paste all code, and press Enter.