Closures in array functions in PHP - Mini Project: Build & Apply

Closures in array functions

📖 Scenario: You have a list of product prices in an online store. You want to apply a discount to some products based on their price.

🎯 Goal: Use a closure (anonymous function) with PHP's array_filter and array_map functions to select products above a certain price and apply a discount.

📋 What You'll Learn

Create an array called prices with the exact values: 100, 50, 200, 150, 80

Create a variable called discount_threshold and set it to 100

Use array_filter with a closure to select prices greater than discount_threshold

Use array_map with a closure to apply a 10% discount to the filtered prices

Print the resulting discounted prices array

💡 Why This Matters

🌍 Real World

Online stores often need to apply discounts to products based on price or other conditions. Using closures with array functions helps write clean and reusable code.

💼 Career

Understanding closures and array functions is important for PHP developers working on e-commerce sites, data processing, and backend logic.

1

Create the prices array

Create an array called prices with these exact values: 100, 50, 200, 150, 80.

PHP

# Create the prices array
# Your code here

Need a hint?

Use square brackets [] to create the array with the exact numbers inside.

2

Set the discount threshold

Create a variable called discount_threshold and set it to 100.

PHP

<?php
$prices = [100, 50, 200, 150, 80];
# Create the discount_threshold variable
# Your code here

Need a hint?

Just assign the number 100 to the variable $discount_threshold.

3

Filter prices above the threshold

Use array_filter with a closure to create a new array called filtered_prices that contains only prices greater than discount_threshold. Use function($price) use ($discount_threshold) as the closure.

PHP

<?php
$prices = [100, 50, 200, 150, 80];
$discount_threshold = 100;
# Filter prices greater than discount_threshold
# Your code here

Need a hint?

The closure needs to access $discount_threshold using use keyword.

4

Apply discount and print results

Use array_map with a closure to create a new array called discounted_prices by applying a 10% discount to each price in filtered_prices. Then print discounted_prices using print_r.

PHP

 $discount_threshold;
});
# Apply 10% discount to filtered_prices and print the result
# Your code here

Need a hint?

Multiply each price by 0.9 to apply a 10% discount. Use print_r to display the array.