//polymorphism  : refer to previous examples' inheritance hierarchy
//superclass: eg27_GradedActivity <- eg32_PassFailActivity <- eg32_PassFailExam : subclass
public class eg34_Polymorphic
{
	public static void main(String[] args)
	{
		//create an array of references
		eg27_GradedActivity[] tests = new eg27_GradedActivity[3];
		//can only access 3 methods in eg27_GradedActivity class
		
		tests[0] = new eg27_GradedActivity();
		tests[0].setScore(95);
		System.out.println("Test 0 score = "+tests[0].getScore()+"; grade = "+tests[0].getGrade() );
		//getGrade() method of eg27_GradedActivity
		
		tests[1] = new eg32_PassFailExam(20, 5, 60);
		System.out.println("Test 1 score = "+tests[1].getScore()+"; grade = "+tests[1].getGrade() );
		//getGrade() method of eg32_PassFailExam
		//override, dynamic binding, determine at runtime which method to call = type of obj referenced
		
		//skipping tests[2]
		//System.out.println(tests[1].getPointsEach() ); this oone won't work due to declaration on first line
	}
}