JAVA

1.can be an object be referenced by a variable of several different data types?

2- Describe two uses for the keyword uses?

3. What is the difference between this and super when these words are used within a constructor definition as the names of methods that are called?

4. Consider the code below, which was discussed in the previous section:

Student joe = new Student("Joe Student", 2001);

System.out.println(joe.toString());

Why is the output on two lines instead of being all on one line?

5. Which of the following lines are legal and which are illegal? The class Undergraduate is a derived class of Student, and Student is a derived class of Person

.a.Person p1 =new Student();

b.Person p2 =new Undergraduate();

c.Student s1 =new Person();

d.Student s2 =new Undergraduate();

e.Undergraduate ug1 =new Person();

f.Undergraduate ug2 =new Student();

g.Object ob =new Student();

h.Student s3 =new Object();