inheritance.pde

//initializing parent class
class A{
  int x;//variable as example
  A(int _x){//constructor
    x = _x;//init
  }
}
//extending class
class Derived extends A{
  int y;//variable as example
  Derived(int _x, int _y){//constructor
    super(_x);//super calls the parent constructor to avoid any errors
    y = _y;//init
  }
}
void main(){
  Derived d = new Derived(0,0);//variable things
}