where are the non-static member variables of a class initialized?

where are the non-static member variables of a class initialized?

within the class declaration or 开发者_StackOverflow社区within the constructor?? thanks

In the Constructor. Constructor is there to initialize the non-static members of class.

class foo
{
    static int num; // static variable don't belong to any particular instance of a class.
    foo(){}
};

So, do it like this in the corresponding source file -

int foo::num = 10 ;

It's within the constructor's initialization list. If a compiler-generated constructor is used then the principle is the same, it's just implicitly generated.

Preferrably in a constructor initialization list: http://www.parashift.com/c++-faq-lite/ctors.html#faq-10.6