Generic function declaration in Swift - Mini Project: Build & Apply

Generic function declaration

📖 Scenario: You are building a small utility in Swift that can work with different types of data without rewriting the same code for each type.

🎯 Goal: Create a generic function that can accept any type of input and return it unchanged. This will help you understand how to write flexible and reusable code in Swift.

📋 What You'll Learn

Create a generic function named identity that takes one parameter called value of a generic type T and returns the same type T.

Use the generic type parameter T in the function declaration.

Call the identity function with an Int value and a String value.

Print the results of the function calls.

💡 Why This Matters

🌍 Real World

Generic functions let you write flexible code that works with many data types, reducing repetition and bugs.

💼 Career

Understanding generics is important for Swift developers to build reusable libraries and APIs.

1

Create a generic function declaration

Write a generic function named identity with a generic type parameter T. The function should take one parameter called value of type T and return a value of type T. Do not write the function body yet.

Swift

// Declare the generic function identity with type parameter T
// Your code here

Need a hint?

Use the syntax func functionName<T>(parameter: T) -> T to declare a generic function.

2

Complete the generic function body

Complete the body of the generic function identity so that it returns the input parameter value unchanged.

Swift

func identity(value: T) -> T {
    // Return the input value unchanged
    // Your code here
}

Need a hint?

The function should simply return the parameter value.

3

Call the generic function with different types

Call the generic function identity with an Int value 42 and assign the result to a variable called intResult. Then call identity with a String value "Hello" and assign the result to a variable called stringResult.

Swift

func identity(value: T) -> T {
    return value
}

// Call identity with Int and String
// Your code here

Need a hint?

Use let variableName = identity(value: someValue) to call the function.

4

Print the results

Print the values of intResult and stringResult using two separate print statements.

Swift

func identity(value: T) -> T {
    return value
}

let intResult = identity(value: 42)
let stringResult = identity(value: "Hello")

// Print the results
// Your code here

Need a hint?

Use print(intResult) and print(stringResult) to display the values.