std::stack<T,Container>::top

 

C++

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std::stack

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stack::top

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stack::push

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stack::pop

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operator==operator!=operator<operator>operator<=operator>=operator<=> (C++20)

std::swap (C++11)

Deduction guides(C++17)

 

reference top();
const_reference top() const;

Returns reference to the top element in the stack. This is the most recently pushed element. This element will be removed on a call to pop(). Effectively calls c.back().

Parameters

(none)

Return value

Reference to the last element

Complexity

Constant

Example

Run this code

#include <stack>
#include <iostream>
 
void reportStackSize(const std::stack<int>& s)
{
    std::cout << s.size() << " elements on stack\n";
}
 
void reportStackTop(const std::stack<int>& s)
{
    // Leaves element on stack
    std::cout << "Top element: " << s.top() << '\n';
}
 
int main()
{
    std::stack<int> s;
    s.push(2);
    s.push(6);
    s.push(51);
 
    reportStackSize(s);
    reportStackTop(s);
 
    reportStackSize(s);
    s.pop();
 
    reportStackSize(s);
    reportStackTop(s);
}

Output:

3 elements on stack
Top element: 51
3 elements on stack
2 elements on stack
Top element: 6

See also

push	inserts element at the top (public member function)
pop	removes the top element (public member function)