Why extensions add capability without modifying in Swift - See It in Action

Why extensions add capability without modifying

📖 Scenario: Imagine you have a simple app that works with numbers. You want to add new features to numbers without changing the original number code. This is like adding new tools to your toolbox without breaking the old ones.

🎯 Goal: You will learn how to use extension in Swift to add new functions to existing types without changing their original code.

📋 What You'll Learn

Create a variable with a number

Create an extension for the Int type

Add a new function inside the extension

Call the new function and print the result

💡 Why This Matters

🌍 Real World

Extensions let developers add new features to existing code safely, like adding new tools to a toolbox without breaking old tools.

💼 Career

Understanding extensions is important for Swift developers to write clean, maintainable, and flexible code in apps.

1

Create a variable with a number

Create a variable called myNumber and set it to 10.

Swift

// Create a variable called myNumber and set it to 10
// Your code here

Need a hint?

Use var myNumber = 10 to create the variable.

2

Create an extension for the Int type

Create an extension for the Int type. Inside it, define a function called squared() that returns the number multiplied by itself.

Swift

var myNumber = 10

// Create an extension for Int with a function squared()
// Your code here

Need a hint?

Use extension Int { func squared() -> Int { return self * self } }.

3

Call the new function on the variable

Call the squared() function on myNumber and store the result in a variable called result.

Swift

var myNumber = 10

extension Int {
    func squared() -> Int {
        return self * self
    }
}

// Call squared() on myNumber and store in result
// Your code here

Need a hint?

Use let result = myNumber.squared() to call the function.

4

Print the result

Print the value of result using print().

Swift

var myNumber = 10

extension Int {
    func squared() -> Int {
        return self * self
    }
}

let result = myNumber.squared()

// Print the result
// Your code here

Need a hint?

Use print(result) to show the output.