where's the FUN in Functions?

[ProgrammingDlux]

I can't figure out how to run this Check Balancing Program. It has no compile time errors, but every time I wanna see the end balance..it outputs the same balance I put in to start. Are my function bodys right? Can anyone help?

#include <iomanip.h>
#include <stdlib.h>

float Dep(float Bal, float Amount)
     { Bal=Bal+Amount;
       return 0;}

float Check(float Bal, float Amount)
     { Bal=Bal-Amount;
       return 0;}

float Charge(float Bal, float Amount)
     { Bal=Bal-Amount;
       return 0;}

float Withdraw(float Bal, float Amount)
     { Bal=Bal-Amount;
       return 0;}


main()
 {  float Bal, Amount; char Comm;

    cout<<"\n BALANCING CHECKBOOK PROGRAM ";
    cout<<"\n --------------------------- ";
    cout<<"\n\n My Account ";
    cout<<"\n Enter Starting Balance : "; cin>>Bal;
    cout<<"\n Command Options: "
        <<"\n d- deposit"
        <<"\n c- check "
        <<"\n s- service charge "
        <<"\n w- withdrawal "
        <<"\n x- exit "<<endl;
    cout<<"\n Enter command: "; cin>>Comm;
    cout<<"\n Enter amount in dollars and cents: "; cin>>Amount;
     while(Comm != 'x')
       {       cout<<"\n Enter another command: "; cin>>Comm;

              if(Comm == 'd')
              {Dep(Bal, Amount);cout<<"\n Enter amount in dollars and cents: "; cin>>Amount;}
         else if(Comm == 'c')
              {Check(Bal,Amount);cout<<"\n Enter amount in dollars and cents: "; cin>>Amount;}
         else if(Comm == 's')
              {Charge(Bal,Amount);cout<<"\n Enter amount in dollars and cents: "; cin>>Amount;}
         else if(Comm == 'w')
              {Withdraw(Bal,Amount);cout<<"\n Enter amount in dollars and cents: "; cin>>Amount;}
         else if(Comm == 'x')
              {cout<<"\n Your New Balance is: $"<<Bal; break;}

       }

      system("PAUSE");
      return 0;
}

[blight2c]

i'll preface with my standard: i don't know much. but your functions aren't returning the float you defined them to. is that it?

[Prelude]

Two things. You pass the values by value to your functions yet you do not return the result of the operation nor try to assign the return value in your main function. So you take the values, change them, discard the result, and print the original value that you entered.

-Prelude

[ProgrammingDlux]

How would I use that in my program...this is the first time I'm using Functions..gimme just one little example ..pleaaaaase!

[Prelude]

Keep the code the same, but change the parameters to your functions to references so that you effect the values passed to the function instead of copies of those values:

void Dep(float &Bal, float &Amount)
{ 
  Bal=Bal+Amount;
}

void Check(float &Bal, float &Amount)
{ 
  Bal=Bal-Amount;
}

void Charge(float &Bal, float &Amount)
{ 
  Bal=Bal-Amount;
}

void Withdraw(float &Bal, float &Amount)
{ 
  Bal=Bal-Amount;
}

-Prelude

[blight2c]

could the same be achieved if he returned bal?

[Prelude]

>could the same be achieved if he returned bal?
Yes

float Check ( float Bal, float Amount )
{ 
  return ( Bal - Amount );
}

-Prelude