My calc program?

I kept getting errors and warnings on this code, but before I post the errors, I am sure you can pick them out by yourselves with this being such a low level code.

Code:

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#include <iostream>

using namespace std;

int add()
{
        unsigned long int a;
        unsigned long int b;
        cout << "\nFirst number: ";
        cin.get >> a;
        cout << "\nSecond number: ";
        cin.get >> b;
        cout << "\nAnswer: ";
        cout << a + b;
        cin.get;
        menu();
        return 0;
}

int subtract()
{
        unsigned long int a;
        unsigned long int b;
        cout << "\nFirst number: ";
        cin.get >> a;
        cout << "\nSecond number: ";
        cin.get >> b;
        cout << "\nAnswer: ";
        cout << a - b;
        cin.get;
        menu();
        return 0;
}

int multiply()
{
        unsigned long int a;
        unsigned long int b;
        cout << "\nFirst number: ";
        cin.get >> a;
        cout << "\nSecond number: ";
        cin.get >> b;
        cout << "\nAnswer: ";
        cout << a * b;
        cin.get;
        menu();
        return 0;
}

int devide()
{
        unsigned long int a;
        unsigned long int b;
        cout << "\nFirst number: ";
        cin.get >> a;
        cout << "\nSecond number: ";
        cin.get >> b;
        cout << "\nAnswer: ";
        cout << a / b;
        cin.get;
        menu();
        return 0;
}
               
int menu()
{
        int choice;
        cout << "1. Add\n";
        cout << "2. Subtract\n";
        cout << "3. Multipply\n";
        cout << "4. Devide\n";
        cout << "\n";
        cout << "Choice: ";
        cin.get >> choice;
        if (choice='1') {
                add();
        }
        else if (choice='2') {
                subtract();
        }
        else if (choice='3') {
                multiply();
        }
        else if (choice='4') {
                devide();
        }
        else {
                cout << "Invalid option.";
                menu();
        }
        return 0;
}

int main()
{
        menu();
        return 0;
}

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Code:

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    cin.get >> a;        // I dunno if this would be a problem, but  try a = cin.get();

    else if (choice='2') // Use == in conditional statements, = assigns a VALUE to the variable

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EDIT: vVv beat me :o

Quote:

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Originally posted by vVv
Your usage of cin.get( ) is wrong. cin.get( ) is a /function/ and it returns the character read. For example

>cin.get >> a;

becomes a = cin.get( ), or simply cin >> a;. Also note that cin overloads the types you supply, so you should make your variables ``char'' instead of ``unsigned int'' if you want to input ascii chars.

>if (choice='1') {

This shouldn't give you an error, but make it ==.

>but before I post the errors, I am sure you can pick them out by
>yourselves with this being such a low level code.

Ignorance. Annoying. Post your errors if you still get any.

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Yea I just noticed the if statement was messed up and fixed that, I am going to go and compile to see what I get.

I did what you said, I am not getting any warnings now, but I am getting two errors-

Quote:

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C:\Windows\Desktop\Programming\calc\clac.cpp(16) : error C2065: 'menu' : undeclared identifier
C:\Windows\Desktop\Programming\calc\clac.cpp(66) : error C2373: 'menu' : redefinition; different type modifiers

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Thanks, it is finally working ;)

I don´t see the purpose of returning 0 in add-, subtract-, multiply-, devide- and menufunctions. Change it to void insteed and remove unnessesary return 0 statements.

Do NOT change the code in main to void main and exclude return 0 or else be prepared to face the wrath of Salem.

2 things mentioned by others.. are okey.. one problem was with cin.get() and other was useage of = instead of == in conditional statement.. but there is one more thing important is that choice is an integer variable then why are you comparing using ' as
if (choice == '1')
this is not goood but it should be as
if (choice == 1)

One more important thing is about menu() function.. when menu is displayed..by correcting your code.. there is no way to get out the menu() I mean to close the program.. so in the menu there must be a choice by which user can terminate the program...
I have edited the program..and code is

Code:

---

#include <iostream>
#include <cstdlib>

using namespace std;
int menu();//You did not declared menu() before using it..
int add()
{
        unsigned long int a;
        unsigned long int b;
        cout << "\nFirst number: ";
        cin >> a;
        cout << "\nSecond number: ";
        cin >> b;
        cout << "\nAnswer: ";
        cout << a + b;
        menu();
        return 0;
}

int subtract()
{
        unsigned long int a;
        unsigned long int b;
        cout << "\nFirst number: ";
        cin >> a;
        cout << "\nSecond number: ";
        cin >> b;
        cout << "\nAnswer: ";
        cout << a - b;
        menu();
        return 0;
}

int multiply()
{
        unsigned long int a;
        unsigned long int b;
        cout << "\nFirst number: ";
        cin >> a;
        cout << "\nSecond number: ";
        cin >> b;
        cout << "\nAnswer: ";
        cout << a * b;
        menu();
        return 0;
}

int devide()
{
        unsigned long int a;
        unsigned long int b;
        cout << "\nFirst number: ";
        cin >> a;
        cout << "\nSecond number: ";
        cin >> b;
        cout << "\nAnswer: ";
        cout << a / b;
        menu();
        return 0;
}
               
int menu()
{
        int choice;
        cout << "1. Add\n";
        cout << "2. Subtract\n";
        cout << "3. Multipply\n";
        cout << "4. Devide\n";
    cout << "5. Exit\n";
        cout << "\n";
        cout << "Choice: ";
        cin >> choice;
        if (choice == 1 ) {
                add();
        }
        else if (choice == 2) {
                subtract();
        }
        else if (choice == 3) {
                multiply();
        }
    else if (choice == 4) {
                devide();
        }
    else if (choice == 5) {
                exit(0);
        }
          else {
                cout << "Invalid option.";
                menu();
        }
        return 0;
}

int main()
{
        menu();
        return 0;
}

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I accually remade it. I was bored and then I thought about remaking it. So here is the new code.

Code:

---

#include <iostream>
       
using namespace std;
       
int main()
{
        char option;
        float a, b;
        cout << "1. Add" << endl;
        cout << "2. Subtract" << endl;
        cout << "3. Multiply" << endl;
        cout << "4. Devide" << endl << endl; // the extra "<< endl" so it will leave a space between the menu and the "Choice" line
        cout << "Choice: ";
        cin >> option;
       
        if (option=='1')
        {
                cout << "\nWhat is the first number?: ";
                cin >> a;
                cout << "\nWhat is the second number?: ";
                cin >> b;
                cout << "\nAnswer: ";
                cout << a+b;
        }
        else if (option=='2')
        {
                cout << "\nWhat is the first number?: ";
                cin >> a;
                cout << "\nWhat is the second number?: ";
                cin >> b;
                cout << "\nAnswer: ";
                cout <<        a-b;
        }
        else if (option=='3')
        {
                cout << "\nWhat is the first number?: ";
                cin >> a;
                cout << "\nWhat is the second number?: ";
                cin >> b;
                cout << "\nAnswer: ";
                cout << a*b;
        }
        else if (option=='4')
        {
                cout << "\nWhat is the first number?: ";
                cin >> a;
                cout << "\nWhat is the second number?: ";
                cin >> b;
                cout << "\nAnswer: ";
                cout << a/b;
        }
        else
        {
                cout << "\nThat is an invalid option.";
        }
        return 0;
}

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Quote:

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Originally posted by Munkey01
I accually remade it. I was bored and then I thought about remaking it. So here is the new code.

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Whoa, what the heck happened to your modularity?
Functions are good.
Modularity is good.
Functions are good.
Modularity is good.
Functions are good.
In short, don't get rid of your functions.

Another suggestion: Give the user an option to use the calculator again if he wants to. Hint: fuctions will make doing this a whole lot easier.

Phew, it's good to know that I'm not the worst programmer on the CBoard:p

LordVirus, that was harsh :rolleyes:

But you were thinking healthy when you tried to implement functions, Monkey. It's the more logical path :D

Quote:

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Originally posted by LordVirusXXP
Phew, it's good to know that I'm not the worst programmer on the CBoard

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And probably not the best!!!

Come on LordVirusXXP, that was rude and inpolite (like my post).

Yeah, I'm definately not the best. But on a helpful note, your if statements are messed up. I certainly hope that helps. (TeeHee!:DZ)

I don't know how far you are planning on going with this calculator idea, but if you want to make it object oriented you could make a calculator class, and use operator+, operator-, operator/, and operator*.

Code:

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...
int a, b, answer;
cout << "enter two numbers to add" << endl;
cin >> a >> b;
answer = mycalc.operator+(a,b);

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something along those lines :)

Quote:

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Originally posted by LordVirusXXP
Phew, it's good to know that I'm not the worst programmer on the CBoard:p

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Well yes I am not very good, yet. But you got to take in the fact I just started a few days before Christmas.