static variable

[Ajaycpp]

Why we need to assign memory explicitly for static variables?

like int Base::m;

can any one please explain?

[Zhuge]

The same reason we need to give a body to a function we have only declared a prototype for. Please think about that and see if you can come up with some specific reasoning yourself. ;)

[Ajaycpp]

but here static int m; is not a functon so how can we declare like that?

[Zhuge]

static int m; is basically a prototype for the variable, saying that the name exists but nothing more than that.