calculator in c++

i think making a calculator is a good idee
but i need a but can i get some help here's the code

#include <stdio.h>
#include <stdlib.h>
#include <iostream.h>
char answer1[200]
char answar2[200]
char calc[200]
int main ()
{
cout ("this program allowes you to calculate like 10+10") <<endl;
cout ("enter number 1") <<endl;
cin.getline (answar1,ziseof(answar1);
cout ("enter second answar" <<endl;
cin.getline (answar2,sizeof(name))
//here must come a code to do + with the answars does anybodu
// knows that and puts it in varubale calc
cout ("answar"<<calc<<"\n" <<endl;
system ("pause");

Help with what?

EDIT: Please consider shortening your signature.

This is my first attempt at helping somebody!

Code:

---

#include <iomanip>
#include <iostream>
#include <fstream>
#include <stdlib>
#include <conio>
#include <time>
#include <ctype>

int main ()
  {
      int x, y;

      cout<<"this program allowes you to calculate like 10+10\n\n";
     
      cout<<"enter number 1: ";
      cin>>x;

      cout<<"enter number 2: ";
      cin>>y;

      x=x+y;
      cout<<"\n\n\nYour total is: ";
      cout<<x;

      getch();

  return 0;
}

---

Quote:

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Originally posted by Noobie
x=x+y;

---

you can also do x += y

Hmm, after looking over your code, I can't help but to wonder why you are using all those ugly global variables and including those completely redundant header files. And, though surprisingly, correct spelling can enormously improve readability :rolleyes: This should work nicely:

Code:

---

#include <iostream>
using namespace std;

#define MAX_CHARS 20

void eatWhiteSpace(char ch[])
{
        int i = 0, t = 0;

        while((ch[i] = ch[t ++]))
        {
                if(ch[i] != ' ')
                        i ++;
        }
}

int main()
{
        char a[MAX_CHARS], b[MAX_CHARS];

        cout << "Enter an addition problem: ";
        cin.getline(a, MAX_CHARS, '\n');

        eatWhiteSpace(a);

        for(int i = 0; a[i]; i ++)
        {
                if(a[i] == '+')
                {
                        for(int t = 0; a[i]; t ++, i ++)
                                b[t] = a[i];

                        a[i + 1] = '\0';
                        break;
                }
        }

        cout << "The sum is " << atoi(a) + atoi(b) << "\n\n";

        return 0;
}

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Calculators without a GUI are kinda wierd. Do it like graphing calculators do it. Input a string, parse it and print the answer. Store variables -- stuff like that

yup..thats what i am working on..a person enter an equation in like

((4+5)*(6-7))/(45) etc...

working with classes to do that...

To get ya started:

Every operator has precedence, and parenthesis "up" that precedence for that block. So lets say we only have

3 operators:

Code:

---

Op:        Name:                Precedence Value:
-----------------------------------------
/        Division        3
*        Multiply        2
+        Addition        1

---

And lets say parenthesis add 10 to that precedence value:

Code:

---

Brace:        Precedence Value:
(        +10
)        -10

[ ] { }    -> same thing

---

Now we parse the string:

Code:

---

String:  2 + (2/3 * 5/6 + 4)
Braces:      +10      -10
PValue:    1  13 12 13 11

---

What we have to do is incorporate a stack. We push (unless they're already there) their l-values and r-values and operate. The operation leaves the answer on the

stack. Ex: pushing 2 values and adding leaves one value on the top of the stack -> the answer.

There are many ways to do this. Here's one way where we start with the highest value operators:

Code:

---

push 2
push 3
divide

push 5
push 6
divide

multiply

push 4
addition

push 2
addition

---

This way uses post-fix "syntax" (make a search; I think that's how you call it). We push all the values from lowest priority to first, then operate all at once:

EDIT: Method two doesn't work, lol, but it can if you do it right, I'm going to sleep now....

Code:

---

push 2
push 4
push 2
push 3
push 5
push 6
divide
divide
multiply
addition
addition

---

And what's left on the stack is the answer! Hope I helped... ;)

Expanding on what speedy5 said, you should search for "building expression trees"

thanks noobie
for your code here's the calcuculator

gamer, you might want to add some extra input validation
what if I enter a letter in stead of a number?

more information:
http://www.augustcouncil.com/~tgibso....html#directly

if you enter 0.5
he shows a really $$$$ answar

PHP Code:

---

#include <iomanip.h>
#include <iostream.h>
#include <fstream.h>
#include <stdlib.h>
#include <conio.h>
#include <time.h>
#include <ctype.h>

int main ()
   { 
      int x, y;

      cout<<"this program allowes you to calculate like 10+10\n\n";
      
      cout<<"enter number 1: ";
      cin>>x;

      cout<<"enter number 2: ";
      cin>>y;

      x=x+y;
      cout<<"\n\n\nYour total is: ";
      cout<<x;
      cout <<"\n\n\n\n\n"<<endl;

      system ("pause");

   return 0;
} 


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Quote:

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Originally posted by gamer
if you enter 0.5
he shows a really $$$$ answar

---

If i remember correct, Integers won't store anything behind the
decimal. Use doubles or floats instead.