Generics means parameterized types. The idea is to allow type (Integer, String, … etc, and user-defined types) to be a parameter to methods, classes, and interfaces. Using Generics, it is possible to create classes that work with different data types.
An entity such as class, interface, or method that operates on a parameterized type is called generic entity.
Why Generics?
Object is the superclass of all other classes and Object reference can refer to any type object. These features lack type safety. Generics adds that type safety feature. We will discuss that type safety feature in later examples.
Generics in Java is similar to templates in C++. For example, classes like HashSet, ArrayList, HashMap, etc use generics very well. There are some fundamental differences between the two approaches to generic types.
Generic Functions:
We can also write generic functions that can be called with different types of arguments based on the type of arguments passed to generic method, the compiler handles each method.
Syntax:
static void genericDisplay (T element) { System.out.println(element); }
Task:
Generic methods are a very efficient way to handle multiple datatypes using a single method. This problem will test your knowledge on Java Generic methods.
Let’s say you have an integer array and a string array. You have to write a single method printArray that can print all the elements of both arrays. The method should be able to accept both integer arrays or string arrays.
You are given code in the editor. Complete the code so that it prints the following lines:
1 2 3 Hello InterviewBit
Do not use method overloading because your answer will not be accepted.