15.9.4. Bounded Type Parameters

Try these first

1. 1.

   What does the syntax <T extends Number> indicate?

   Hint

   Think about what types can inherit from Number.

2. 2.

   Can we pass a String to a method defined as <T extends Number>?

   Hint

   Consider the hierarchy of Java classes.

3. 3.

   What does <T extends Number> signify?

   • T can be any type
   • T must be a subclass of Number
   • T can be a superclass of Number

   Hint

   Reflect on inheritance in Java.

4. 4.

   True or False: Bounded type parameters can help prevent runtime errors.

   • True
   • False

   Hint

   Remember how generics enhance type safety.

5. 5.

   Implement a method that takes in two types of numbers, Integer and Double, and returns a string describing which one is larger. Use bounded type parameters.

   Hint

   Ensure proper use of the Comparable interface for comparisons.

6. 6.

   Design a generic class Calculator<T extends Number> which can perform addition on any type extending Number.

   Hint

   Consider how to use the doubleValue() method for numeric operations.