Loop acting crazy

[djru]

I'm at the very end of this calculator program, everything is working perfectly. Besides the fact I cannot get this loop to end. I can't end it with

while(op!= q)

Because i need it to display the final result. How I have it now the loop is supposed to end with num2= quit, when I input this into the program it does something crazy and just keeps going and going and going and going until I just exit the IDE, and if I don't have a way out of the loop after it displays the final result the program just asks for another number input. Maybe the professor doesn't want the loop to end and I am just overthinking I don't know, but this is what I have.

#include <iostream>
#include <math.h> 


using namespace std;

//Prototypes

//Retrieves the operator, operand and returns operator
//and operand

void scan_data(char, double);

//Reads operator and operand and uses switch statement
//to perform correct operator on the operand

double do_nex_op(char, double, double&);

//Reads result and outputs the result of the operator
//and the operand

float do_next_op(double);


int main()
{
    char op;
    double num2;
    double sum;

    
  cout<< "This program is a very basic calculator \n";
  cout<< "use only operators +,-,*,/, or ^";
  cout<<" to raise a number to a power\n\n";

    
  //display operator and operand
    
    scan_data(op, num2);

    
return 0;    

}

// function to obtain original values

void scan_data(char op, double num2)
{
 
   double num;
   double result;
  
      num = do_nex_op ( op, num2, num);
  
      result = do_next_op(num);

}

// performs operation based on operator input

double do_nex_op(char op, double num2, double& num)
{
   num = 0;
  
  cout<< "Enter a valid operator:\n";
  cin >> op;
  
  cout<< "Enter any number:\n";
  cin >> num2;
       switch (op)
        {
            case'+':
                cout << "\n+"<< num2;
                num = num + num2;
                cout<<"\n\nresult so far " << num;
                break;
            case '-':
                cout << "\n-"<< num2;
                num = num - num2;
                cout <<"\n\nresult so far " << num;
                break;
            case '*':
                cout << "\n*"<< num2;
                num = num * num2;
                cout <<"\n\nresult so far "<< num;
                break;
            case '/':
                cout << "\n/"<< num2;
                num = num / num2;
                cout <<"\n\nresult so far "<< num;
                break;
            case '^':
                cout << "\n^"<< num2;
                num = pow(num, num2);
                cout <<"\n\nresult so far "<< num;
                break;
            case 'q':
                cout <<"\nq" <<" 0";
                cout << "\n\nfinal result is"<< num;
            default:
                cout<<"\n\nInvalid operator";
                
                
          }
    
       return (num);
}
// initiate loop
float do_next_op(double num)
{
    double num2;
    char op;
    
    cout<<"\nEnter Next Opertion:\n"<< endl;
    cin>> op;
    
    cout <<"\nEnter next Number: \n"<<endl;
    cin>> num2;
    switch(op)
    {
            case'+':
                cout<<"\n+"<< num2;
                num= num2 + num;
                cout<< "\nresult so far is "<< num;
                break;
            case'-':
                cout<<"\n -"<< num2;
                num= num2 - num;
                cout<<"\nresult so far is "<< num;
                break;
            case'*':
                cout<<"\n*"<< num2;
                num= num2 * num;
                cout<<"\nresult so far is "<< num;
                break;
            case'/':
                cout<<"\n/"<<num2;
                num= num / num2;
                cout << "\nresult so far is "<< num;
                break;
            case'^':
                cout<<"\n ^"<< num2;
                num= pow(num, num2);
                cout << "\nresult so far is "<< num;
                break;
            case 'q':
                cout<<"\nq "<<"0";
                cout<<"\nFinal result is: \n";
                cout<< num;
            default:
                cout<<"\nNot a valid operator";
    }
    
    while (num2 != 'quit')
  {     cout<<"\n\nEnter Next Operation:\n";
        cin>> op;
        cout<<"Enter next number: \n";
        cin>> num2;
     
    switch(op)
    {
            case'+':
                cout<<"\n+"<< num2;
                num= num2 + num;
                cout<< "\nresult so far is "<< num;
                break;
            case'-':
                cout<<"\n -"<< num2;
                num= num2 - num;
                cout<<"\nresult so far is "<< num;
                break;
            case'*':
                cout<<"\n*"<< num2;
                num= num2 * num;
                cout<<"\nresult so far is "<< num;
                break;
            case'/':
                cout<<"\n/"<<num2;
                num= num / num2;
                cout << "\nresult so far is "<< num;
                break;
            case'^':
                cout<<"\n ^"<< num2;
                num= pow(num, num2);
                cout << "\nresult so far is "<< num;
                break;
            case 'q':
                cout<<"\nq "<<"0";
                cout<<"\nFinal result is: \n";
                cout<< num;
            default:
                cout<<"\nNot a valid operator";
    }        
 }              
                    
                    
   return 0;         


}

I know i should just create a seperate function for the switch statement, but when I tried that all hell broke loose and a whole new set of problems arose, so i just utilized copy and paste..

[buffbill]

try:
while (op =!q){

[djru]

This is crazy, I KNOW i tried that earlier and it didn't work, now it did, thanks I appreciate it. One last question why after I enter q and the final result is shown, and now the loop ends, is the program still displaying my default cout ex:

Enter Next Operation:
q
Enter next number:
0

q 0
Final result is:
8
Not a valid operator

and then the program stops running, do you have any idea why its displaying my default case?

[Peter87]

You forgot to put a break statement at the end of the case 'q' so it will just go on and run the code in the default case below.