What is the purpose of a stack in a program?

The stack in programming is used for storing data in dynamic memory based on the LIFO (Last-In, First-Out) principle. Main applications include:

• Storing local variables of functions.
• Storing return addresses when calling functions.
• Passing arguments to functions.
• Temporarily storing data during operations (for example, in compilers for parsing expressions).

// Example of using a stack for local variables
func myFunction() {
    var stackVariable: Int = 10 // This variable is allocated on the stack
    let anotherVariable: String = "Hello" // This variable is also on the stack
    print(stackVariable)
}

// When myFunction is called, its local variables and return address are placed on the stack.
// After the function completes, they are removed from the stack.
myFunction()

The stack is managed automatically; memory allocation and deallocation happen very quickly. The size of the stack is limited.