can I declare a class variable inside that class method?

[John Black]

Hi,
Suppose I have a class,

class MyClass{
public:
MyClass();
MyClass(MyClass);

int func();
};

Then can I declare a MyClass object inside MyClass::func()?

int MyClass::func(){
MyClass obj;
<......>
}

 

[Russell Hanneken]

Suppose I have a class,

class MyClass{
public:
MyClass();
MyClass(MyClass);

Suppose you wrote

MyClass x;
MyClass y(x);

Because the copy constructor parameter is passed by value, a copy of x
is made, and the copy is sent to the copy constructor. But to make the
copy, the MyClass copy constructor would have to be invoked. And then
the argument would have to be copied, using the MyClass copy constructor
again. And so on...

The point is, your copy constructor should take a reference, not a copy:

MyClass(MyClass const &);

int func();
};

Then can I declare a MyClass object inside MyClass::func()?

int MyClass::func(){
MyClass obj;
<......>
}

Sure.

 

[jeffc]

Hi,
Suppose I have a class,

class MyClass{
public:
MyClass();
MyClass(MyClass);

int func();
};

Then can I declare a MyClass object inside MyClass::func()?

int MyClass::func(){
MyClass obj;
<......>
}

Yes. Just don't do this
int MyClass::func()
{
MyClass obj;
obj.func();
}