Check Even/Odd numbers within a range in Java 8 Streams

In this post, we will see “How to check odd or even numbers within a certain range using Java 8 Streams API”.

Easiest representation of Java 8 Streams power to test Odd or Even numbers within a certain range...!!! Share on X

Let’s say: In this particular example, we are extracting the odd and even numbers within the range of 10 to 25

Note: you can specify any range you would like to check for in place of the one we used in this example.

Example

import java.util.stream.*;

public class CheckOddOrEvenNumberWithinRangeJava8 {

    public static void main(String args[]) {

        retrieveOddNumbersWithinRange(10, 25);

        retrieveEvenNumbersWithinRange(10, 25);

    }

    public static void retrieveOddNumbersWithinRange(int start, int end) {
        System.out.println("ODD NUMBERS WITHIN THE RANGE OF 10 AND 25");

        //1st way
        System.out.println("\n 1st way: \n");
        IntStream.range(start, end + 1).filter(i - > i % 2 != 0).forEach(System.out::println);

        //2nd way (traditional way - before java 8)
        System.out.println("\n 2nd way: \n");
        for (int i = start; i <= end; i++) {
            if (i % 2 != 0) {
                System.out.println(i);
            }
        }

        //3rd way
        System.out.println("\n 3rd way: \n");
        Stream.iterate(start, i - > i + 1).filter(CheckOddOrEvenNumberWithinRangeJava8::isOdd).limit(8).forEach(System.out::println);
    }

    public static void retrieveEvenNumbersWithinRange(int start, int end) {
        System.out.println("\n\n EVEN NUMBERS WITHIN THE RANGE OF 10 AND 25");

        //1st way
        System.out.println("\n 1st way: \n");
        IntStream.range(start, end + 1).filter(i - > i % 2 == 0).forEach(System.out::println);

        //2nd way (traditional way - before java 8)
        System.out.println("\n 2nd way: \n");
        for (int i = start; i <= end; i++) {
            if (i % 2 == 0) {
                System.out.println(i);
            }
        }

        //3rd way
        System.out.println("\n 3rd way: \n");
        Stream.iterate(start, i - > i + 1).filter(CheckOddOrEvenNumberWithinRangeJava8::isEven).limit(8).forEach(System.out::println);
    }

    public static boolean isOdd(int number) {
        return number % 2 != 0;
    }

    public static boolean isEven(int number) {
        return number % 2 == 0;
    }
}

Output:

ODD NUMBERS WITHIN THE RANGE OF 10 AND 25

 1st way: 

11
13
15
17
19
21
23
25

 2nd way: 

11
13
15
17
19
21
23
25

 3rd way: 

11
13
15
17
19
21
23
25


 EVEN NUMBERS WITHIN THE RANGE OF 10 AND 25

 1st way: 

10
12
14
16
18
20
22
24

 2nd way: 

10
12
14
16
18
20
22
24

 3rd way: 

10
12
14
16
18
20
22
24

That’s it, Java 8 Streams API is so powerful and notice how shortened and understandable the code is.

Do you like this Post? – then check my other helpful posts:

• Double the even / odd numbers of a specified ArrayList using Streams
• Double the numbers of specified ArrayList using Streams

Other Useful References:

• java.util.stream by Oracle
• Java 8 Stream by Baeldung