JAVA

how to use map, filter and reduce in Java

import java.util.stream.IntStream;

public class StreamOperations {
	public static void main(String[] args) {
		int[] values = {3, 10, 6, 1};

		// Sum of values via reduce method
		System.out.printf("Sum: %d%n",
			IntStream.of(values)
					 .reduce(0, (x, y) -> x + y)); // Sum: 20
		// Product via reduce
		System.out.printf("Product: %d%n",
			IntStream.of(values)
					 .reduce(1, (x, y) -> x*y)); // Product: 180
		// Even values multiplied by 10 
		// and displayed in sorted order
		// Printing: 60 100
		IntStream.of(values)
				 .filter(value -> value % 2 == 0)
				 .map(value -> value * 10)
				 .sorted()
				 .forEach(value -> System.out.printf("%d ", value));	
	}
}

java stream filter map reduce example

String[] myArray = { "this", "is", "a", "sentence" };
String result = Arrays.stream(myArray)
                .reduce("", (a,b) -> a + b);