How to Access the Top Element of a Stack in C++?

In C++, The stack is a container adapter that provides a Last-In-First-Out (LIFO) type of data structure in which insertion and deletion are done at the end only. In this article, we will learn how to access the top element of a stack in C++.

Example:

Input:
myStack = {10, 20, 30, 40}

Output:
Top Element: 40

Find the Top Element of a Stack in C++

To access the top element of a stack in C++, we can use the std::stack::top() function that retrieves the top element of the stack (if the stack is not empty). This function is mainly used to reference the top element of the stack.

C++ Program to Access the Top Element of a Stack

C++

// C++ Program to illustrate how to access the top element
// of the stack
#include <iostream>
#include <stack>
using namespace std;

// Driver code
int main()
{
    // Creating a stack of integers
    stack<int> stackData;

    // Pushing elements onto the stack
    stackData.push(10);
    stackData.push(20);
    stackData.push(30);
    stackData.push(40);

    // Accessing the top element of the stack using top()
    int res = stackData.top();

    // Printing the top element
    cout << "Top Element: " << res << endl;

    // Printing the stack
    cout << "Stack Elements: ";
    while (!stackData.empty()) {
        cout << stackData.top() << " ";
        stackData.pop();
    }
    cout << endl;

    return 0;
}

Output

Top Element: 40
Stack Elements: 40 30 20 10 

Time Complexity: O(1)
Auxiliary Space: O(1)