Java 8 java.util.function.Function with example program

• java.util.function.Function introduced in java 8 for functional programming.
• Function(T,R) will be used in streams where to take one type of  object and convert to another and return. 
• And this Function() supports methods like apply(), andThen(), compose() and  identity() etc.
• Lets see an example on java.util.function.Function.

#1: Java Example program on java.util.function.Function

1. package com.instanceofjava.java8;
2. 
   
3. import java.util.function.Function;
4. /**
5.  * @author www.Instanceofjava.com
6.  * @category interview questions
7.  * 
8.  * Description: java 8 java.util.function.Function example program
9.  *
10.  */
11. public class Java8Function {
12. 
    
13. public static void main(String[] args) {
15. Function<Integer, String> function = (n) -> {
16. return "Number received: "+n;
17. };
18. 
    
19. System.out.println(function.apply(37));
20. System.out.println(function.apply(64));
21. 
    
22. }
23. 
    
24. }

Output:

1. Number received: 37
2. Number received: 64

#2: Java example program on Function and explain used of addThen() and compose() methods