Structs are value types (copy on assign) in Swift - Mini Project: Build & Apply

Understanding Structs as Value Types in Swift

📖 Scenario: Imagine you have a simple app that keeps track of a book's details. You want to see how changing one copy of a book's information does not affect another copy.

🎯 Goal: You will create a Book struct, make a copy of it, change the copy, and then print both to see that the original stays the same. This shows how structs in Swift are value types and copy on assign.

📋 What You'll Learn

Create a struct called Book with two properties: title and author, both of type String.

Create a variable originalBook of type Book with title "Swift Basics" and author "John Appleseed".

Create a variable copiedBook and assign it the value of originalBook.

Change the title of copiedBook to "Advanced Swift".

Print the title of both originalBook and copiedBook to show they are different.

💡 Why This Matters

🌍 Real World

Structs are used in apps to represent simple data like user profiles, settings, or items. Understanding value types helps keep data safe from accidental changes.

💼 Career

Many Swift jobs require knowing when to use structs versus classes. This knowledge helps write safer and more efficient code.

1

Create the Book struct

Create a struct called Book with two String properties: title and author.

Swift

# Your code here

Need a hint?

Use the struct keyword and define two variables inside it.

2

Create the original Book variable

Create a variable called originalBook of type Book with title set to "Swift Basics" and author set to "John Appleseed".

Swift

struct Book {
    var title: String
    var author: String
}

# Your code here

Need a hint?

Create a variable and use the struct's initializer with the exact values.

3

Copy originalBook to copiedBook and change the title

Create a variable called copiedBook and assign it the value of originalBook. Then change the title of copiedBook to "Advanced Swift".

Swift

struct Book {
    var title: String
    var author: String
}

var originalBook = Book(title: "Swift Basics", author: "John Appleseed")

# Your code here

Need a hint?

Assign originalBook to copiedBook and then update the title property of copiedBook.

4

Print titles of both books

Print the title of originalBook and copiedBook on separate lines to show they are different.

Swift

struct Book {
    var title: String
    var author: String
}

var originalBook = Book(title: "Swift Basics", author: "John Appleseed")

var copiedBook = originalBook
copiedBook.title = "Advanced Swift"

# Your code here

Need a hint?

Use two print statements, one for each book's title.