Map method in Javascript - Mini Project: Build & Apply

Using the Map Method to Double Numbers

📖 Scenario: You have a list of prices for items in a store. You want to create a new list where each price is doubled, for example, to show the price after a special sale that doubles the cost.

🎯 Goal: Build a small program that uses the map method to double each number in an array of prices.

📋 What You'll Learn

Create an array called prices with the exact numbers: 10, 20, 30, 40, 50

Create a variable called multiplier and set it to 2

Use the map method on prices with a function that multiplies each price by multiplier

Store the result in a variable called doubledPrices

Print the doubledPrices array

💡 Why This Matters

🌍 Real World

Using the <code>map</code> method helps when you want to change every item in a list, like updating prices or adjusting scores.

💼 Career

Many programming jobs require working with lists of data and transforming them efficiently, and <code>map</code> is a common tool for this.

1

Create the prices array

Create an array called prices with these exact numbers: 10, 20, 30, 40, 50.

Javascript

// Your code here

Need a hint?

Use square brackets [] to create an array and separate numbers with commas.

2

Create the multiplier variable

Create a variable called multiplier and set it to the number 2.

Javascript

const prices = [10, 20, 30, 40, 50];
// Your code here

Need a hint?

Use const to create a variable that does not change.

3

Use map to double each price

Use the map method on the prices array with a function that multiplies each price by multiplier. Store the result in a variable called doubledPrices.

Javascript

const prices = [10, 20, 30, 40, 50];
const multiplier = 2;
// Your code here

Need a hint?

Use array.map(item => item * multiplier) to create a new array with each item multiplied.

4

Print the doubled prices

Write a console.log statement to print the doubledPrices array.

Javascript

const prices = [10, 20, 30, 40, 50];
const multiplier = 2;
const doubledPrices = prices.map(price => price * multiplier);
// Your code here

Need a hint?

Use console.log(doubledPrices) to show the new array in the console.