**Course Title:** Swift Programming: From Basics to Advanced Development **Section Title:** Advanced Features: Generics and Extensions **Topic:** Create a generic data structure or function demonstrating the use of generics.(Lab topic) **Introduction** In the previous topic, we learned about generics and their benefits in Swift. Generics allow us to create reusable code that can work with different data types, making our code more flexible and efficient. In this lab topic, we will create a generic data structure or function that demonstrates the use of generics. **Creating a Generic Data Structure** Let's create a generic data structure called `Stack` that can store elements of any type. A stack is a type of data structure that follows the Last-In-First-Out (LIFO) principle, where the last element added to the stack is the first one to be removed. ```swift // Create a generic Stack data structure public struct Stack<T> { private var elements: [T] = [] public mutating func push(_ element: T) { elements.append(element) } public mutating func pop() -> T? { guard !elements.isEmpty else { return nil } return elements.removeLast() } public func isEmpty() -> Bool { return elements.isEmpty } } ``` In this example, we create a generic `Stack` struct that takes a type parameter `T`. The `elements` array is declared as `[T]`, which means it can store elements of any type `T`. We define three methods: `push`, `pop`, and `isEmpty`. **Using the Generic Data Structure** Now that we have created our generic `Stack` data structure, let's use it to store elements of different types. ```swift // Create a Stack of Integers var intStack = Stack<Int>() intStack.push(10) intStack.push(20) print(intStack.pop()) // prints 20 print(intStack.pop()) // prints 10 // Create a Stack of Strings var stringStack = Stack<String>() stringStack.push("Hello") stringStack.push("World") print(stringStack.pop()) // prints "World" print(stringStack.pop()) // prints "Hello" ``` As you can see, our generic `Stack` data structure can work with different data types, including integers and strings. **Creating a Generic Function** Let's create a generic function called `merge` that takes two arrays of any type `T` and returns a new array that contains all the elements from both arrays. ```swift // Create a generic merge function public func merge<T>(_ arr1: [T], _ arr2: [T]) -> [T] { return arr1 + arr2 } ``` In this example, we create a generic `merge` function that takes two arrays of type `[T]` and returns a new array of type `[T]`. **Using the Generic Function** Now that we have created our generic `merge` function, let's use it to merge two arrays of different types. ```swift // Merge two arrays of Integers let intArr1 = [1, 2, 3] let intArr2 = [4, 5, 6] let mergedIntArr = merge(intArr1, intArr2) print(mergedIntArr) // prints [1, 2, 3, 4, 5, 6] // Merge two arrays of Strings let strArr1 = ["Hello", "World"] let strArr2 = ["Swift", "Programming"] let mergedStrArr = merge(strArr1, strArr2) print(mergedStrArr) // prints ["Hello", "World", "Swift", "Programming"] ``` As you can see, our generic `merge` function can work with different data types, including integers and strings. **Conclusion** In this lab topic, we created a generic data structure called `Stack` and a generic function called `merge`. We demonstrated how generics can be used to create reusable code that can work with different data types. Generics are a powerful feature in Swift that can help us write more flexible and efficient code. **Additional Resources** * Apple Developer Documentation: [Generics](https://docs.swift.org/swift-book/LanguageGuide/Generics.html) * Swift by Tutorials: [Generics](https://www.raywenderlich.com/books/swift-by-tutorials/v23.0/chapters/24-generics) **Exercise** Create a generic data structure called `Queue` that can store elements of any type. A queue is a type of data structure that follows the First-In-First-Out (FIFO) principle, where the first element added to the queue is the first one to be removed. **Leave a Comment/Ask for Help** If you have any questions or need help with the exercise, please leave a comment below.