How do I don't write the function 3 times?

Question

Code:
switch(x)
{
case 1:
Class1 obj;
obj.somefunc();
break;
case 2:
Class2 obj;
obj.somefunc();
break;
case 3:
Class3 obj;
obj.somefun();
break;
}

All the classes are derived from:

class Base
{
public:
somefunc() {}
} ;

How do I write the function somefunc() only once and not three times?
Because if I declare the object in the switch statment and then write obj.somefunc() (out of the switch statment) then I get an Error.

Could someone Please tell me how I do it???

Answer 1

Looks like a case for polymorphism.

It goes something like this:
#include <memory>

std::unique_ptr<Base> obj;

switch( x )
case 1: obj.reset( new Class1 ); break;
case 2: obj.reset( new Class2 ); break;
... etc

if( obj ) obj->somefunc();

( Don't forget to define a virtual destructor in your Base class! )

Answer 2

write obj. somefunc() after switch case...
swich()
{
...
}
obj. somfunc() ;
Make sure obj exist by one of switch case..