Chapter 17.5, Problem 17.17CP

Explanation of Solution

Constraining a type parameter of a generic class with an upper bound:

“Yes”, type parameter of generic class can be constrained with an upper bound using the keyword extends.

Explanation:

• The keyword extends is used to restrict the type parameter of generic class.
• A type to an upper bound is constrained by the keyword extends.
• In order to declare the type parameter with an upper bound, the developer list the name of type parameter, followed by the keyword extends, and followed by its upper bound.
• Example:

public class exam<T extends Number> //Line1

{ //Line2

    private T to; //Line3

    private T ra; //Line4

    public exam(T tot, T rank) //Line5

    { //Line6

        to= tot; //Line7

        ra=rank; //Line8

    } //Line9

    public static void main (String[] args) //Line10

    { //Line11

        exam<Integer> e1= new exam<>(2,3); //Line12

        exam<Double> e2= new exam<>(466...

Explanation of Solution

Constraining a type parameter of a generic class with a lower bound:

“Yes”, type parameter of generic class can be constrained with lower bound using the keyword super.

Explanation:

• The keyword super is used to restrict the type parameter.
• A type to a lower bound is constrained by the keyword super.
• In order to declare the type parameter with lower bound, the developer list the name of type parameter, followed by the keyword super, and followed by its lower bound.
• Example:

public class exam<T super Integer> //Line1

{ //Line2

    private T to; //Line3

    private T ra; //Line4

    public exam(T tot, T rank) //Line5

    { //Line6

        to= tot; //Line7

        ra=rank; //Line8

    } //Line9

    public static void main (Str...