Function declaration in Javascript - Mini Project: Build & Apply

Function declaration

📖 Scenario: You are creating a simple calculator that adds two numbers. To do this, you will write a function that takes two numbers and returns their sum.

🎯 Goal: Build a JavaScript function called addNumbers that takes two parameters and returns their sum. Then call this function with specific numbers and display the result.

📋 What You'll Learn

Declare a function named addNumbers with two parameters: a and b

Inside the function, return the sum of a and b

Call the function addNumbers with the arguments 5 and 7

Print the result of the function call using console.log

💡 Why This Matters

🌍 Real World

Functions help organize code into reusable blocks, like a recipe you can use many times. This is useful in calculators, games, websites, and more.

💼 Career

Knowing how to write and use functions is a basic skill for any programming job. It helps you write clean, easy-to-understand, and reusable code.

1

Create the function declaration

Write a function declaration named addNumbers that takes two parameters called a and b. Inside the function, return the sum of a and b.

Javascript

// Write the function declaration for addNumbers with parameters a and b
// Your code here

Need a hint?

Use the function keyword followed by the function name and parentheses with parameters. Use return to send back the sum.

2

Call the function with arguments

Call the function addNumbers with the arguments 5 and 7 and store the result in a variable called result.

Javascript

function addNumbers(a, b) {
    return a + b;
}

// Call addNumbers with 5 and 7 and save to result
// Your code here

Need a hint?

Use const result = addNumbers(5, 7); to call the function and save the answer.

3

Print the result

Use console.log to print the value of the variable result.

Javascript

function addNumbers(a, b) {
    return a + b;
}

const result = addNumbers(5, 7);

// Print the result variable
// Your code here

Need a hint?

Use console.log(result); to show the sum in the console.

4

Run and check the output

Run the program and check that the output printed is 12.

Javascript

function addNumbers(a, b) {
    return a + b;
}

const result = addNumbers(5, 7);

console.log(result);  // Check output

Need a hint?

The console should show the number 12 because 5 + 7 = 12.