distinct() Example

Example:
import java.util.Arrays;
import java.util.List;

public class DistinctFlight {
    public static void main(String[] args) {
        System.out.println("main() [Start]");

        List<Integer> numbers = Arrays.asList(6,10, 20, 10, 3, 3, 2, 4,6);
       
        numbers
        .stream()
        .filter(num->num%2==0)
        .distinct()
        .forEach(System.out::println);
       
        System.out.println("main() [End]");
    }
}

Ouput:
main() [Start]
6
10
20
2
4
main() [End]

Explanation:

 .filter(num->num%2==0) :

• filter takes the lamda expression as an argument. 
• It takes a lamda expression having functional interface having abstract method which take one argument and return boolean result. 
• It returns the Stream of given type parameter. 

  .distinct():

• this method works on the stream returned from the filter method
• It returns the Stream with unique element.

  .forEach(System.out::println):

• This method works on the stream returned from the distinct method
• This is a terminal operation method because it doesnt return the stream.
• All the previous streams maintained as pipeline and processed when this method get called
• This method takes a consumer functional interface lamda expression or method reference as argument and it consumes the data of previous streams. Here it consumes and display each element.