✅ Swift Stack Using Array

struct Stack<T> {
    private var elements: [T] = []

    // Push an element onto the stack
    mutating func push(_ value: T) {
        elements.append(value)
    }

    // Pop an element from the top of the stack
    mutating func pop() -> T? {
        return elements.popLast()
    }

    // Peek at the top element without removing it
    func peek() -> T? {
        return elements.last
    }

    // Check if the stack is empty
    func isEmpty() -> Bool {
        return elements.isEmpty
    }

    // Get the current size of the stack
    func size() -> Int {
        return elements.count
    }
}

🧪 Example Usage:

var stack = Stack<Int>()

stack.push(10)
stack.push(20)
stack.push(30)

print(stack.peek() ?? "Empty")  // Output: 30
print(stack.pop() ?? "Empty")   // Output: 30
print(stack.size())             // Output: 2
print(stack.isEmpty())          // Output: false

stack.pop()
stack.pop()
print(stack.isEmpty())          // Output: true