Difference between Function and Predicate in Java 8

Function and Predicate both functional interface was introduced in Java 8 to implement functional programming in Java.

Function interface is used to do the transformation.It can accepts one argument and produces a result. On the other side, Predicate can also accept only one argument but it can only return boolean value. It is used to test the condition.

Example of Predicate

public class Main {
   public static void main(String args[]) {
      List<Integer> numList = new ArrayList<>();
      numList.add(5);
      numList.add(10);
      Predicate<Integer> pred = i -> i > 5;
      numList.stream().filter(pred).forEach(i -> System.out.println(i));
   }
}

Example of Function

public class Main {
   public static void main(String args[]) {
      List<Integer> numList = new ArrayList<>();
      numList.add(78);
      numList.add(10);
      Function<Integer, Integer> fun = i -> i / 2;
      numList.stream().map(fun).forEach(System.out::println);    
   }
}