I\'m using one of the approaches to class inheritance in JavaScript (as used in the code I\'m modifying), but do not understand how to attach additional functionality for a
The variable var parentVar = inVar; is a local and private variable available only in the Parent() function and visible only to functions defined in the same scope (Parent()).
I think that best way here would be to modify the Parent class in such way that the parentVar wouldn't be private, but public:
function Parent(inVar) {
this.parentVar = inVar;
}