Operations Performed on a Stack

1. Push

The push operation adds an element to the top of the stack.

push(stack, element) {
  stack.push(element);
}

where:

• stack is the stack to which the element is to be added
• element is the element to be added

2. Pop

The pop operation removes and returns the element at the top of the stack.

pop(stack) {
  if (stack.isEmpty()) {
    throw new Error("Stack is empty");
  }
  return stack.pop();
}

where:

• stack is the stack from which the element is to be removed

3. Peek

The peek operation returns the element at the top of the stack without removing it.

peek(stack) {
  if (stack.isEmpty()) {
    throw new Error("Stack is empty");
  }
  return stack.peek();
}

where:

• stack is the stack from which the element is to be retrieved

4. IsEmpty

The isEmpty operation checks if the stack is empty.

isEmpty(stack) {
  return stack.isEmpty();
}

where:

• stack is the stack to be checked

5. Size

The size operation returns the number of elements in the stack.

size(stack) {
  return stack.size();
}

where:

• stack is the stack whose size is to be determined

Example

The following program demonstrates the operations on a stack:

#include 
#include 

using namespace std;

int main() {
  stack stack;

  // Push elements onto the stack
  stack.push(1);
  stack.push(2);
  stack.push(3);

  // Pop an element from the stack
  int poppedElement = stack.pop();

  // Peek at the element at the top of the stack
  int topElement = stack.top();

  // Check if the stack is empty
  bool isEmpty = stack.empty();

  // Get the size of the stack
  int size = stack.size();

  // Print the results
  cout << "Popped element: " << poppedElement << endl;
  cout << "Top element: " << topElement << endl;
  cout << "Is stack empty: " << isEmpty << endl;
  cout << "Size of stack: " << size << endl;

  return 0;
}

Output:

Popped element: 3
Top element: 2
Is stack empty: false
Size of stack: 2