[Applied] Build a Simple Inventory Management Tool

In this lesson you will build a simple inventory management program using a Swift dictionary, putting everything you have learned together. This is for anyone searching for "Swift inventory management applied implementation".

Use the dictionary you have learned about to build a program that tracks stock levels. A dictionary looks up and updates values quickly by key, which makes it one of the most heavily used data structures in real applications.

The sample code adds to the stock with items["apple", default: 0] += 10, giving a fallback for a key that does not exist yet with default:, then reduces it with items["apple", default: 0] -= 3 and prints the latest values.

A common stumbling block for beginners is the ! when reading back out of the dictionary. The sample force-unwraps with items["apple"]!, which risks a crash if the key might be missing.

The classes, error handling, and arrays you have learned here are core Swift skills that carry over directly into real iOS app development. Well done for getting this far.

📖 Reference code

var items: [String: Int] = [:]
items["apple", default: 0] += 10
items["orange", default: 0] += 5
items["apple", default: 0] -= 3
print("apple: \(items["apple"]!)")
print("orange: \(items["orange"]!)")

✍️ Your code

Type your code, then press "Run"

🧪 This site can't compile or run Swift directly, so it checks on the spot whether what you typed matches the reference code (scoring happens entirely in your browser — nothing is sent anywhere).