Trying to make calculator type program

[ziodice]

Can someone please tell me how to fix this? I'm trying to make a calculator that can divide, add, and subtract, but I get an error on line 16 I believe, saying "expected primary expression before ')' token". Here is the code:

#include <iostream>
#include <cmath>
#include <cstdlib>
using namespace std;

         int main() {
             cout << "Hello" << endl;
             cout << "Please ender your desired calculation" << endl;
             int A;
             int B;
             int C;
             int D;
             cin >> A;
             cin >> B;
             cin >> C;
             if (B == -)
             {
             cout << A - C
             } 
             else if (B == +)
             {
             cout << A + C
             }
             else if (B == /)
             {
             cout << A / C
             }
             cin.ignore();
             cin.get();
             }

I thank you in advanced for any help. Oh and I'm kinda an idiot, so sorry if the answer is obvious

[emyr666]

A few points...

* B should be a char not an int.

* You need quotes around the operators in the program e.g.

if (B == '-') {

*Try to indent better.

*Use

int main(int argc, char **argv) {

*Don't use uppercase for general variable names.

[ziodice]

I have another problem now. I can't figure out how to make the program stay open and let you keep putting in new calculations. Can someone tell me how?

[emyr666]

Read about while loops.

[ziodice]

When I did a while loop, it made the program start then end instantly, doing the oppisite effect >.<

[ziodice]

I have ANOTHER problem. Man I'm an idiot.
Okay, I got the while loop, this is the code right now

#include <iostream>
#include <cmath>
#include <cstdlib>
using namespace std;

         int main(int argc, char **argv) {
             cout << "Hello" << endl;
             cout << "Please ender your desired calculation" << endl;
             int A;
             char B;
             int C;
             int D;
             while (true)
             {
             cin >> A;
             cin >> B;
             cin >> C;
             if (B == '-')
             {
             cout << A - C;
             } 
             else if (B == '+')
             {
             cout << A + C;
             }
             else if (B == '/')
             {
             cout << A / C;
             }
             else if (B == '*')
             {
                  cout << A * C;
                  }
                  system("cls");
             cin.ignore();
             cin.get();
             
             }
             }

I can run it, I can do the first calculation, but when I do the second one, it glitches and displays the answer of the first calculation

[Nisheeth]

First of all, using arguments in main() is not necessary.

I have corrected the code.
The problem was lost with system("cls");

Heres the code(with proper indenting):

#include <iostream>
#include <cmath>
#include <cstdlib>

using namespace std;

int main() 
{
	int A;
	char B;
	int C;
	cout << "Hello" << endl;
	while (true)
    {		
		cout << endl << "Please ender your desired calculation" << endl;
		cin >> A;
		cin >> B;
		cin >> C;
        
		if (B == '-')
        {
			cout << A - C;
        }

        else if (B == '+')
        {
			cout << A + C;
        }

        else if (B == '/')
        {
			cout << A / C;
        }

        else if (B == '*')
        {
        cout << A * C;
        }

        cin.ignore();
        cin.get();
	}
}

EDIT:
Why did you create an integer D?
It was not used anywhere in the program. Just a waste of memory

[ziodice]

Integer D was meant for a feature of the program I hadn't yet added, it was supposed to be part of the code that let's you do one step algebra in the calculator, but I haven't decided exactly how I was going to code that out.
And can you please tell me what was wrong with system("cls")? is it because some people say system() stuff is evil? Haha.

[Nisheeth]

one step algebra

What do you mean by that?

[ziodice]

Like this: Say you input x = 2 + 8 it would tell you: x = 10

[Nisheeth]

Do you know about string parsing?
you could use that for it.

EDIT:
I had made a calculator sometime back as well, I had used a class for it
(though it could be made without it).
You can see the code here:
http://pastebin.com/F8hZUmEb

It takes the input in form of a single string like : 25*51
and will break it into three parts, 25, 51 and *
and then it functions the same as yours