Array map function in PHP - Mini Project: Build & Apply

Array map function

📖 Scenario: You work in a bakery that wants to update the prices of some pastries. You have a list of prices, and you want to increase each price by 10% to cover new costs.

🎯 Goal: Use the array_map function in PHP to create a new list of updated prices with a 10% increase.

📋 What You'll Learn

Create an array called prices with the values 2.50, 3.00, 4.25, 5.00

Create a variable called increase_rate and set it to 0.10

Use array_map with a function that increases each price by increase_rate

Print the new array of updated prices

💡 Why This Matters

🌍 Real World

Updating prices in a list is common in stores and online shops when costs change.

💼 Career

Knowing how to use <code>array_map</code> helps you process lists of data efficiently in PHP, a skill useful for web developers.

1

Create the initial array of prices

Create an array called prices with these exact values: 2.50, 3.00, 4.25, 5.00.

PHP

# Your code here

Need a hint?

Use square brackets [] to create the array and separate values with commas.

2

Set the increase rate

Create a variable called increase_rate and set it to 0.10 to represent a 10% increase.

PHP

<?php
$prices = [2.50, 3.00, 4.25, 5.00];
# Your code here

Need a hint?

Use the = sign to assign the value to the variable.

3

Use array_map to increase prices

Use array_map with a function that takes each price and returns the price increased by increase_rate. Store the result in a variable called updated_prices.

PHP

<?php
$prices = [2.50, 3.00, 4.25, 5.00];
$increase_rate = 0.10;
# Your code here

Need a hint?

Use an anonymous function with use ($increase_rate) to access the variable inside the function.

4

Print the updated prices

Print the updated_prices array using print_r to see the new prices.

PHP

<?php
$prices = [2.50, 3.00, 4.25, 5.00];
$increase_rate = 0.10;
$updated_prices = array_map(function($price) use ($increase_rate) {
    return $price * (1 + $increase_rate);
}, $prices);
# Your code here

Need a hint?

Use print_r($updated_prices); to display the array.