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Need some help with class scopes?

BPA (2)
When I run it, it says that 'in member function 'void calc::over() error main() was not declared in this scope'. I don't know how to make it recognize it!



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#include <iostream>
using namespace std;

class calc
{

public:
    void add()
{
	double a,b,c;
	cout<<"Put in the first number: ";
	cin>>a;
	cout<<"\n";
	cout<<"Put in the second number: ";
	cin>>b;
	cout<<"\n";
	c = a + b;
	cout<<c;
}

void sub()
{
	double a,b,c;
	cout<<"Put in the first number: ";
	cin>>a;
	cout<<"\n";
	cout<<"Put in the second number: ";
	cin>>b;
	cout<<"\n";
	c = a - b;
	cout<<c;
}

void mult()
{
	double a,b,c;
	cout<<"Put in the first number: ";
	cin>>a;
	cout<<"\n";
	cout<<"Put in the second number: ";
	cin>>b;
	cout<<"\n";
	c = a * b;
	cout<<c;
}

void div()
{
	double a,b,c;
	cout<<"Put in the first number: ";
	cin>>a;
	cout<<"\n";
	cout<<"Put in the second number: ";
	cin>>b;
	cout<<"\n";
	c = a / b;
	cout<<c;
}

void sq()
{
	double a,b;
	cout<<"Put in the number to be squared: ";
	cin>>a;
	cout<<"\n";
	b = a*a;
	cout<<b;
}

void over()
{
	char a;
	cout<<"My good sir I believe you have gone over the limit."<<endl;
	cout<<"Would you like a do-over?"<<endl;
	cout<<"y or n?"<<endl;
	cin>>a;
	if (a=='y') {main();cout<<"\n";}
	else if (a=='n') {cout<<"Then my good sir, get out.";}
}


};


int main()
{
	int choice;
	char a;
	calc calcob;
	cout<<"Do you want to do addition, subtraction, etc.?"<<endl;
	cout<<"1 - Addition"<<endl;
	cout<<"2 - Subtraction"<<endl;
	cout<<"3 - Multiplication"<<endl;
	cout<<"4 - Division"<<endl;
	cout<<"5 - Square a Number"<<endl;
	cin>>choice;
	cout<<"\n";
	if (choice==1) calcob.add();
	else if (choice==2) calcob.sub();
	else if (choice==3) calcob.mult();
	else if (choice==4) calcob.div();
	else if (choice==5) calcob.sq();
	else calcob.over();
	cout<<endl;
	cout<<endl;
	cout<<endl;
	cout<<"Do you want to calculate more, y or n?"<<endl;
	cin>>a;
	if (a=='y')
	{
	cout<<endl;
	cout<<endl;
	cout<<endl;
	main();
	}
	cin.get();
	cin.get();
	return 0;
}


bcrawford (15)
if (a=='y') {main();cout<<"\n";}

In line 77, lose the main() and you'll be good to go.
BPA (2)
Hmm. I was wanting to shave it so if the user entered an invalid number (aka below 1 and above 5) it would ask them for a do-over, completely restarting a program.
ui uiho (382)
why use a class? struct would be better with only variables whose scopes are in single functions.
Peter87 (11234)
Why would struct be better when class is the same thing?

Using namespace is more appropriate because it doesn't make much sense having a calc object without state. To use a namespace instead just change class calc to namespace calc, remove calc calcob; from line 89, change calcob.add(); to calc::add(); and do the same with the other function calls.
Peter87 (11234)
Also calling main() is not allowed so don't that. Maybe you could have a function returning value that you use as a loop condition for a loop in main. The loop just have to contain all the code that should be repeated.
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