JAVA EE: How to use the Intermediate operations[match and reduce] of Java 8 Stream

Monday 23 October 2017

How to use the Intermediate operations[match and reduce] of Java 8 Stream | Streams in Java 8

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https://www.youtube.com/watch?v=BAdEgMA96xo&list=UUhwKlOVR041tngjerWxVccw

StreamDemo1.java

import java.util.Arrays;
import java.util.List;

/**
 * Terminal operation : match()
 */
public class StreamDemo1
{
    public static void main(String[] args)
    {
        List<String> list = Arrays.asList("Ball", "Cat", "Dog", "Apple");

        /*
         * match() operation returns a boolean depending upon the condition
         * applied on stream data.
         */
        boolean result = list.stream().anyMatch((s) -> s.startsWith("D"));
        System.out.println(result);
    }
}

Output

true

StreamDemo2.java

import java.util.stream.IntStream;

/**
 * Terminal operation : reduce()
 */
public class StreamDemo2
{
    public static void main(String[] args)
    {
    
        /*
         * reduce() operation combines the stream elements into one using a
         * BinaryOperator.
         * 
         */
        int result = IntStream.of(1, 2, 3, 4).reduce(0, (a, b) -> a + b);
        System.out.println(result);
    }

}