C++ unable to use peek() function in stack

Question

I am trying to use the peek function in Visual Studio 2010 with these libraries:

#include "stdafx.h"
#include <string>
#include <string.h>
#include <fstream>
#include <iostream>
#include <string.h>
#include <vector>
#include <stack>

However, I cannot use the peek function in the stack:

void dfs(){
    stack<Node> s;
    s.push(nodeArr[root]);
    nodeArr[root].setVisited();
    nodeArr[root].print();
    while(!s.empty()){
        //peek yok?!
        Node n=s.peek();        
        if(!n.below->isVisited()){
            n.below->setVisited();
            n.below->print();
            s.push(*n.below);
        }
        else{
            s.pop();
        }
    }
}

I get the error:

Error 1 error C2039: 'peek' : is not a member of 'std::stack<_Ty>'

What am I doing wrong?

`stack` reference: http://en.cppreference.com/w/cpp/container/stack — hmjd, Mar 30 '12 at 21:19

score 6 · Answer 1 · answered Mar 30 '12 at 21:17

6

I think you want to use

s.top();

instead of peak.

answered Mar 30 '12 at 21:17

Jarosław Gomułka

4,935
18
24

score 5 · Accepted Answer · answered Mar 30 '12 at 21:17

5

There's no peek function in std::stack.

Are you looking for top()?

void dfs(){
    stack<Node> s;
    s.push(nodeArr[root]);
    nodeArr[root].setVisited();
    nodeArr[root].print();
    while(!s.empty()){
        //peek yok?!
        Node n=s.top();   // <-- top here
        if(!n.below->isVisited()){
            n.below->setVisited();
            n.below->print();
            s.push(*n.below);
        }
        else{
            s.pop();
        }
    }
}

answered Mar 30 '12 at 21:17

Luchian Grigore

253,575
64
457
625

Thank you for all so much. in msdn, when i saw reference to peek, i guess i am in the true way. but you are right, i was wrong. thank you again for replies. – Saliha Uzel Mar 30 '12 at 22:07

score 2 · Answer 3 · answered Mar 30 '12 at 21:18

2

There is no peek function in std::stack. For a reference, please see stack

It looks as if you are using the functionality as top would be. For a reference on top, take a look at this reference.

answered Mar 30 '12 at 21:18

josephthomas

3,256
15
20

score 1 · Answer 4 · answered Mar 30 '12 at 21:20

1

Your code has stack, but you actually wanted to use Stack. They are two different things.

answered Mar 30 '12 at 21:20

TJD

11,800
1
26
34

Here's the doc on the Stack you wanted: http://msdn.microsoft.com/en-us/library/1w32446f.aspx#Y0 – TJD Mar 30 '12 at 21:23

C++ unable to use peek() function in stack

4 Answers4