Dictionary methods and default values in Swift - Mini Project: Build & Apply

Dictionary methods and default values

📖 Scenario: You are managing a small fruit store. You want to keep track of how many fruits you have in stock.

🎯 Goal: Build a Swift program that uses a dictionary to store fruit counts, safely access values with default counts, and update the stock.

📋 What You'll Learn

Create a dictionary called fruitStock with exact fruit counts

Create a variable called defaultCount with the value 0

Use the dictionary's default value feature to get counts safely

Update the stock count for a fruit using dictionary methods

Print the final stock counts

💡 Why This Matters

🌍 Real World

Managing inventory counts in a store or warehouse where some items may not be in stock yet.

💼 Career

Understanding dictionary methods and default values is essential for safe data handling in app development and backend programming.

1

Create the initial fruit stock dictionary

Create a dictionary called fruitStock with these exact entries: "Apple": 10, "Banana": 5, "Orange": 8

Swift

# Create the dictionary fruitStock with exact fruit counts
# Your code here

Need a hint?

Use Swift dictionary syntax with square brackets and colons.

2

Add a default count variable

Create a variable called defaultCount and set it to 0

Swift

var fruitStock = ["Apple": 10, "Banana": 5, "Orange": 8]
# Create defaultCount variable set to 0
# Your code here

Need a hint?

Use let or var to create the variable.

3

Use dictionary default value to get counts safely

Create a variable called mangoCount and set it to the count of "Mango" in fruitStock using the dictionary's default value feature with defaultCount

Swift

var fruitStock = ["Apple": 10, "Banana": 5, "Orange": 8]
let defaultCount = 0
# Get mangoCount using fruitStock["Mango", default: defaultCount]
# Your code here

Need a hint?

Use the dictionary subscript with default: to avoid nil.

4

Update stock and print results

Increase the count of "Banana" in fruitStock by 3 using the dictionary's default value feature and then print the updated fruitStock dictionary

Swift

var fruitStock = ["Apple": 10, "Banana": 5, "Orange": 8]
let defaultCount = 0
let mangoCount = fruitStock["Mango", default: defaultCount]
# Increase Banana count by 3 and print fruitStock
# Your code here

Need a hint?

Use the dictionary subscript with default: to add 3 to "Banana" count, then print the dictionary.