我丢失了一些东西，并且尝试调试了一段时间（对c ++来说是新的）

Question

I do not know why the proggram isnt working. I am just testing out a program to see how classes work. what does static do?(I looked up what it does but could I get some explaining). And how could I improve the structure of the code?

Source.cpp

#include <iostream>
#include <math.h>
#include <cstdlib>
#include <cmath>
#include <iomanip>

#include "Source1.cpp"

using namespace std;

    main() {
        float sum1, sum2;
        cout << "Sum1 \n";
        cin >> sum1;
        cout << "Sum2 \n";
        cin >> sum2;
        cout << how_to_add::addition(sum1,sum2) << endl;
        return 0;
    }

Source1.cpp

class how_to_add {
    float sum1, sum2, added;

public:
    static float addition(float sum1, float sum2) {
        float added = sum1 + sum2;
        return added;
    }
};

This is the error I'm having:

1>------ Build started: Project: Project1, Configuration: Debug x64 ------
1>Source.cpp
1>c:\users\lisa\documents\visual studio 2017\projects\project1\project1\source.cpp(11): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>Done building project "Project1.vcxproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Answer 1

In C, the way you declared main , that is without explicitly stating the return type, it would not give you an error, but your C++ compiler doesn't like it (and it's probably compiling in a restricted mode since that should only give you an warning), apparently. So I would suggest you to change:

main() {
    ...

to

int main() {
    ...
    return 0;

Answer 2

Why you name the source file as ".cpp"? Use ".h" instead of ".cpp".