griddynamics

class Singleton {
	private obj
	Singleton() {
		if (obj == null) {

		}
	}
}




class parent {

	fun(){parent}

}

class child extends parent{

fun(){child}
}


child obj = new parent();
Obj.fun() 

parent obj = new child();
Obj.fun() 


……………...
class parent {




}

class child extends parent {

fun(){child}
}


child obj = new parent();
Obj.fun() child

parent obj = new child();
Obj.fun()  null

………

class parent {


fun(){parent}

}

class child extends parent{


}


child obj = new parent();
Obj.fun()



parent obj = new child();
Obj.fun()

………

class parent {


static fun(){parent}

}

class child extends parent{

static  fun(){child}
}


child obj = new parent();
Obj.fun()

parent obj = new child();
Obj.fun()










Requirement


interface SpecialInterface (
	fun1() 
	fun2()
	fun3()
	fun4()
	fun5()
)

class SpecailClass1 {
	public fun1() 
	public fun2()
	fun3()
	fun4()
	fun5()
}

class SpecailClass2 {
	fun1() 
	fun3()
}

class SpecailClass3 {
	fun1() 
	fun2()
	fun3()
}