An object oriented implementation of stack using arrays in C++.

Stack_ArrayImplementation_OOP.cpp

// Stack - Object oriented implementation using arrays
#include <iostream>
using namespace std;
#define MAX_SIZE 101 

class Stack
{
private:
  int A[MAX_SIZE];  // array to store the stack
	int top;   // variable to mark the top index of stack. 
public:
	// constructor
	Stack()
	{
		top = -1; // for empty array, set top = -1
	}

	// Push operation to insert an element on top of stack. 
	void Push(int x) 
	{
	  if(top == MAX_SIZE -1) { // overflow case. 
			printf("Error: stack overflow\n");
			return;
		}
		A[++top] = x;
	}
 
	// Pop operation to remove an element from top of stack.
	void Pop() 
	{
		if(top == -1) { // If stack is empty, pop should throw error. 
			printf("Error: No element to pop\n");
			return;
		}
		top--;
	}
 
	// Top operation to return element at top of stack. 
	int Top() 
	{
		return A[top];
	}
 
	// This function will return 1 (true) if stack is empty, 0 (false) otherwise
	int IsEmpty()
	{
		if(top == -1) return 1;
		return 0;
	}

	// ONLY FOR TESTING - NOT A VALID OPERATION WITH STACK 
	// This function is just to test the implementation of stack. 
	// This will print all the elements in the stack at any stage. 
	void Print() {
		int i;
		printf("Stack: ");
		for(i = 0;i<=top;i++)
			printf("%d ",A[i]);
		printf("\n");
	}
};

int main()
{
    // Code to test the implementation. 
    // calling Print() after each push or pop to see the state of stack. 
	Stack S;
	S.Push(2);S.Print();
	S.Push(5);S.Print();
	S.Push(10);S.Print();
	S.Pop();S.Print();
	S.Push(12);S.Print();
}

I am sorry but I have a little doubt,....we defined a function in public as Stack which sets the value of top as -1. But we never called it in the main function, then why the stack is initialized with top = -1.

Stack is a constructor.
It will be called automatically when an object is created in int main()

But if i am not wrong, the basic functionality of pop() function in stack is to delete the recent value and also return the deleted Value to the Calling Function
.int pop(){ if (isEmpty()) { cout<<"ERROR! No Element to POP\t"; } return A[top--]; };

stdio needs to be included.

actually iostream is enough in cpp language

stdio needs to be included.

actually iostream is enough in cpp language

he said that because printf is used in code instead of cout.