Calculator

[BaDDBLooD]

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// Name: myCalc.cpp
// Author: Joel Zimmerman
// Date: May 03, 2005
// Description: Calculator that does Addition, Subtraction, Multiplication
// Division, Modulus and the Cube of an integer.

#include <iostream>

int main()
{
   int number1;
   int number2;
   int choice;
   char indicator;
   
   cout << "Welcome to my Calculator it will perform the following functions:" << endl
        << "1) Addition" << endl   
        << "2) Subtraction" << endl   
        << "3) Multiplication" << endl
        << "4) Division" << endl
        << "5) Modulus" << endl
        << "6) Cube" << endl;
     
   do
   {
      cout << "Choose Operator: ";
      cin >> choice;
     
      cout << "Enter First Digit: ";
      cin >> number1;
     
      cout << "Enter Second Digit: ";
      cin >> number2;
     
      switch(choice)
      {
         case 1: cout << endl << "The answer is: " << number1 + number2 << endl;
               break;
         case 2: cout << endl << "The answer is: " << number1 - number2 << endl;
               break;
         case 3: cout << endl << "The answer is: " << number1 * number2 << endl;
               break;
         case 4: cout << endl << "The answer is: " << number1 / number2 << endl;
               break;
         case 5: cout << endl << "The answer is: " << number1 % number2 << endl;
               break;
         default: cout << endl <<"You chose invalid selection" << endl;
      }
     
      cout << endl << "Do you want to enter another (y or n)? ";
      cin >> indicator;   
   } while((indicator == 'Y' || indicator == 'y'));
 
  return 0;
}



I am not sure how to go about the "Cubing"

I don't want to cube two numbers, only one.

Ideas/suggestions about ways i could do this would be greatly appreciated.

Also, how do i check if my Number1 and Number2 are actually numbers?

[MyndFyre]

I am not sure how to go about the "Cubing"

I don't want to cube two numbers, only one.

Ideas/suggestions about ways i could do this would be greatly appreciated.

Also, how do i check if my Number1 and Number2 are actually numbers?

I don't know about actual C runtime functions to check if number1 and number2 are actually numbers.  When I compiled and ran in MSVC++ 2003, the program just exited if I input a non-number.

I wrote a function called getnum:

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// gets a number from the console.
// maxDigits: [in] maximum number of digits to accept
// *pNum: [out]value from console.
// return value: whether or not the operation completed successfully.
bool getnum(unsigned short int maxDigits, long int *pNum) {
unsigned int i;
char curVal;
long int temp = 0;
bool okay = false;

for (i = 0; i < maxDigits; i++)
{
curVal = getchar();
if (curVal >= '0' && curVal <= '9') {
// valid character
temp *= 10;
temp += (curVal - '0');
okay = true;
} else {
break;
}
}
// reads the end-of-line character
fseek(stdin, 1, SEEK_CUR);
*pNum = temp;

return okay;
}

getnum takes two parameters.  The first is the maximum number of digits it should accept.  The second is a pointer to the location where it should store the result of the input.  The return value indicates whether any number was input; if it was only invalid text, the function returns false.

To cube a value, simply multiply it by itself two more times:

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case 6: cout << endl << "The answer is: " << number1 * number1 * number1 << endl;
break;

Note that you don't need a second number input to do the cube function.

Aside from that, I changed around some of your other functions.  First, I redeclared your variables:

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   long int number1;
   long int number2;
   long int choice;
   char indicator;
   bool gotnum1 = false;
   bool gotnum2 = false;

Note that I included two booleans (you'll see why in a minute), and changed your other three int choices to long ints.  That was to establish type compatibility with the getnum function -- getnum can return values up to 32 bits in length.

Then I changed your initial prompt:

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  choice = 0;
  cout << "Choose Operator: ";
  bool okay = false;
  do {
   okay = getnum(1, &choice);
  } while (okay && (choice >= 1) && (choice <= 6));

As long as someone is entering a choice outside of 1 to 6, it will keep prompting them.  Note that only the first number is considered.

I also changed your input prompts to use getnum instead of cin.  It checks for the number to be okay, and if it was not input, prompts to insert the number:

Code Select Expand


  do
  {
cout << "Enter First Digit: ";
gotnum1 = getnum(9, &number1);
  } while (gotnum1 == false);
     
  if (choice >= 1 && choice <= 5)
  {
  do
  {
cout << "Enter Second Digit: ";
gotnum2 = getnum(9, &number2);
  } while (gotnum2 == false);
  }


All told, this is what I used in VC++ 2003:

Code Select Expand


// Calc.cpp : Defines the entry point for the console application.
//
#pragma once
// Name: myCalc.cpp
// Author: Joel Zimmerman
// Date: May 03, 2005
// Description: Calculator that does Addition, Subtraction, Multiplication
// Division, Modulus and the Cube of an integer.

//#include "stdafx.h"
#include <iostream>

//protos
bool getnum(unsigned short int, long int*);
int main();


using namespace std;

int main()
{
   long int number1;
   long int number2;
   long int choice;
   char indicator;
   bool gotnum1 = false;
   bool gotnum2 = false;
   
   cout << "Welcome to my Calculator it will perform the following functions:" << endl
        << "1) Addition" << endl   
        << "2) Subtraction" << endl   
        << "3) Multiplication" << endl
        << "4) Division" << endl
        << "5) Modulus" << endl
        << "6) Cube" << endl;
     
   do
   {
  choice = 0;
      cout << "Choose Operator: ";
  bool okay = false;
  do {
  bool okay = getnum(1, &choice);
  } while (okay && (choice >= 1) && (choice <= 6));
           
  do
  {
cout << "Enter First Digit: ";
gotnum1 = getnum(9, &number1);
  } while (gotnum1 == false);
     
  if (choice >= 1 && choice <= 5)
  {
  do
  {
cout << "Enter Second Digit: ";
gotnum2 = getnum(9, &number2);
  } while (gotnum2 == false);
  }
     
      switch(choice)
      {
         case 1: cout << endl << "The answer is: " << number1 + number2 << endl;
               break;
         case 2: cout << endl << "The answer is: " << number1 - number2 << endl;
               break;
         case 3: cout << endl << "The answer is: " << number1 * number2 << endl;
               break;
         case 4: cout << endl << "The answer is: " << number1 / number2 << endl;
               break;
         case 5: cout << endl << "The answer is: " << number1 % number2 << endl;
               break;
case 6: cout << endl << "The answer is: " << number1 * number1 * number1 << endl;
break;
         default: cout << endl <<"You chose invalid selection" << endl;
      }
     
      cout << endl << "Do you want to enter another (y or n)? ";
      cin >> indicator;
  // reads the end-of-line character
  fseek(stdin, 1, SEEK_CUR);
   } while((indicator == 'Y' || indicator == 'y'));
 
  return 0;
}

// gets a number from the console.
// maxDigits: [in] maximum number of digits to accept
// *pNum: [out]value from console.
// return value: whether or not the operation completed successfully.
bool getnum(unsigned short int maxDigits, long int *pNum) {
unsigned int i;
char curVal;
long int temp = 0;
bool okay = false;

for (i = 0; i < maxDigits; i++)
{
curVal = getchar();
if (curVal >= '0' && curVal <= '9') {
// valid character
temp *= 10;
temp += (curVal - '0');
okay = true;
} else {
break;
}
}
// reads the end-of-line character
fseek(stdin, 1, SEEK_CUR);
*pNum = temp;

return okay;
}

Hope it helps

[DarkMinion]

Every time I see 'cout', I want to blow my brains out.

[OnlyMeat]

Every time I see 'cout', I want to blow my brains out.

Why's that then? if you don't like the object orientated features of c++/stl stick to C. Pretty simple.

[Arta]

Every time I see 'cout', I want to blow my brains out.

Me too 

[DarkMinion]

I can manage just fine without Captain Know-It-All telling me what I need to be doing.

[R.a.B.B.i.T]

Yeah, the cout's are ugly.  Also, you can reduce that switch by a shitload if you just declare one more variable.  The output is all the same minus the value.