Java Interview Guide : 200+ Interview Questions and Answers - Generics

This video tutorial introduces the concept of generics in Java, explaining how they allow for the creation of flexible and type-independent programs. It provides an example of a non-generic MyList class and demonstrates how to convert it into a generic class. The tutorial also covers how to restrict generic types using 'extends' and 'super', and explains the creation and use of generic methods. Overall, the video highlights the benefits of generics in making code more adaptable and reusable.

What is the primary purpose of using generics in Java?

• To allow methods and classes to work with different data types

• To simplify the syntax of Java code

• To improve the security of Java applications

• To make programs run faster

In the context of generics, what does the placeholder 'T' represent?

• A class name

• A specific data type

• A generic type parameter

• A method name

How can you restrict a generic type to only accept subclasses of a specific class?

• By using the 'extends' keyword

• By using the 'instanceof' keyword

• By using the 'implements' keyword

• By using the 'super' keyword

What is the effect of using 'T extends Number' in a generic class?

• It allows only primitive types

• It restricts the type to String and its subclasses

• It restricts the type to Number and its subclasses

• It allows any type to be used

Which keyword is used to specify that a generic type must be a superclass of a specific class?

• instanceof

• implements

• super

• extends

What is a generic method in Java?

• A method that is faster than regular methods

• A method that can operate on any type specified at runtime

• A method that can only operate on strings

• A method that can only be used in generic classes

What is the benefit of using generics in method declarations?

• It allows the method to handle different types safely

• It simplifies the method's logic

• It makes the method faster

• It reduces the method's memory usage