adding problem

Hi,
i am new to cprogramming and i want to do this thing. all in all i have 2 problems



1)how do you add answers?

Code:

A+B=ans1
C+D=ans2
ans1+ans2=ans3//i cant do this part

2)Next problem is that i cant add switches is there something i am doing wrong?
i wanted to add cases.

Code:

#include <cstdlib>
#include <iostream>

using namespace std;

int main(int argc, char *argv[])
{
    int A,B,C;
    double total;
    int cash,product;
    double change;
    
    switch (product){
    case 1:
    printf("how many product A: \n");
    cin>>A;
    break;
    
    case 2:
    printf("how many product B: \n");
    cin>>B;
    break;
    
    case 3:
    printf("how many product C: \n");
    cin>>C;
    break;
    }
    
    total=(case 1*10)+(case 2*20)+(case 3*30);
    \\ unit price of product A is 10, product B is 20, product C is 30
    printf("total amout due is: %lf  \n", total);
    
    printf("enter amount paid by customer: \n");
    cin>>cash;
    
    
    do{
    change=total-cash;\\still not working
    printf("total change will be:    \n", change);
    }
    while(total>=cash);
    


    
        
    system("PAUSE");
    return EXIT_SUCCESS;
}

Your right (rvalue) and left (lvalue) values are switched.

Code:

int ans1 = A + B;
int ans2 = C + D;
int ans3 = ans1 + ans2;

The rvalue should be where you do your equations and the lvalue should be a place to store the result. Sorry, I don't have the technical terms to describe rvalue and lvalue.

For your switch, you are testing for product which hasn't been assigned a value.

Sorry for all the posts ... how are you learning C++? Your program is more mangled than any other I've ever seen.

i only put it that way so that it can be explained easily. for the switch this is my first time to encounter a problem where i should add the. sorry if it is all messed up.

It's perfectly fine that it's all messed up. It's a part of learning. How are you teaching yourself C++?