Identifier "stack" (my class) is undefined even though headers are properly included

Question

In my source file when I define my object s, Visual Studios says Identifier "stack" is undefined. I'm pretty sure I've separated the headers correctly but I don't know why I'm getting this error. Also side note when I put everything together in one source file and compile it, it just exits immediately without any reason. Thanks for the help in advance.

This is the source file

// pa3.cpp : Defines the entry point for the console application.
//

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

using namespace std;

int main()
{
    //int count;
    stack s; //assign s object to stack

    string input;
    cout << "Please enter the name of the input file: \n";
    //cin >> input;

    getline(cin, input);
    ifstream file(input);
    string readline;

    //ifstream file(input);

    while (getline(file, readline)) //take first line of file and assign to readline
    {
        s.push(readline); //send it off to push

        s.retrieveUPPER();
        //file.close();
        system("pause");
    }



    return 0;
}

This is the stack.h file

//#pragma once
#include "stdafx.h"
#include <iostream>
#include <string>
#include <fstream>

//#include <ctype.h>

using namespace std;

class stack
{
public:
    int count;
    void push(string);
    //void pop();
    void check(string);
    void retrieveUPPER();

private:
    static string firstline[1];
    static string diskeywords[3];
    static char upperword[100];
    static char lowerword[100];
    static char operatorsarr[100];
    static char delimitersarr[100];
 };

This is the stack.cpp

#include "stack.h"
#include "stdafx.h"
#include <iostream>


string stack::firstline[1] = { 0 };
string stack::diskeywords[3];

char stack::upperword[100];
char stack::lowerword[100];
char stack::operatorsarr[100];
char stack::delimitersarr[100];

void stack::retrieveUPPER()
{
    for (int i = 0; i < 100; i++)
    {
        cout << upperword[i] << "\n";
    }
}

void stack::push(string readline)
{
    firstline[0] = readline;
    count++;
    check(readline);

}

void stack::check(string readline)
{
    int length;
    char letter;
    int leftperenthe = 0;
    int rightperenthe = 0;
    //int capital;
    //int wordFOR;
    //int wordBEGIN;

    //char keywords[3][8] = { "FOR", "BEGIN", "END" };
    char operators[] = "+-=*/;";
    char delimiters[] = { ',',';' };


    length = readline.length();
    for (int i = 0; i < length; i++)
    {
        for (int j = 0; j < 5; j++)
        {
            letter = readline[i];
            if (isupper(letter)) //if capital letter 
            {
                upperword[i] = letter;
            }
            else if (islower(letter)) //if lowercase letter
            {
                lowerword[i] = letter;
            }
            else if (letter == operators[j]) //if encounters a operator
            {
                operatorsarr[i] = letter;
            }
            else if (letter == delimiters[j]) //if encounters a delimiter
            {
                delimitersarr[i] = letter;
            }
            else if (letter = ' ') //if encounters a space
            {
                lowerword[i] = ' ';
                operatorsarr[i] = ' ';
                delimitersarr[i] = ' ';
            }
            else if (letter = '(') //if left perenthesis
            {
                leftperenthe++;
            }
            else if (letter = ')') //if right perenthesis
            {
                rightperenthe++;
            }
        }
    }
}

Answer 1

I also had a similar situation:

#include<iostream>
#include<stack.h>
#include<vector>

using namespace std;
int main();
std::vector<int>stickPan (std::vector<int>arr)
{
    stack<int>s;
...
}

I used VScode, used mingw-w64, and added paths for * .h files to .json files, but it didn't work. Errors are reported:

1. identifier "stack" is undefined.
2. type name is not allowed.
3. identifier "s" is undefined