4 Ways to Check if Array Contains a Specific Value in Java8? IntStream and Arrays.asList Tutorial

This is the simplest and complete solution for your if you want to check if ArrayList contains specific value such as String, Integer, Long or Double.

With the combination of Java7 and Java8 – there are 4 different ways you could perform contains check.

• Legacy String.contains() method
• Java8’s IntStream -> anyMatch() method
• Java8’s LongStream -> anyMatch() method
• Arrays.asList() method

We are going to discuss and check all above 4 methods in this Java Program. This java tutorial will work if you have below questions:

• How can I test if an array contains a certain value?
• check if array contains value in java
• java array contains int
• check if array contains string javascript

If you wonder, is there any way to override contains() method in Java? Well, then follow detailed tutorial on how to override contains() / findMe() method by yourself.

Let’s get started on implementing program with all above 4 methods:

Step-1

Let’s understand first our logic and what we are going to do in this Java tutorial.

• Create Java class CrunchifyCheckIfContains.java
• Create int[] crunchifyIntArray with 15 elements in it
• Print (system.out.println) all 15 elements
• Then Test-1: get Random 5 values and check
  • if value contains then we will print Matched
  • if value doesn’t match then print No Match
• Test-2: Perform same check with Java8 Utility using IntStream -> anyMatch()
• Test-3: Create crunchifyLongArray with 15 elements and perform check with Java8 Utility using LongStream -> anyMatch()
• Test-4: Perform same contains check using Arrays.asList() method

Step-2

Copy complete below program in Eclipse IDE.

package crunchify.com.tutorials;

import java.util.Arrays;
import java.util.List;
import java.util.stream.IntStream;
import java.util.stream.LongStream;

/**
 * @author Crunchify.com 
 * version: 1.0
 */

public class CrunchifyCheckIfContains {
	public static void main(String[] args) {

		int crunchifyRandomNo;

		// Let's create integer array with 15 values in it
		int[] crunchifyIntArray = new int[15];
		for (int i = 1; i <= 14; i++) {
			crunchifyRandomNo = (7 + (int) (Math.random() * ((95 - 7))));
			crunchifyIntArray[i] = crunchifyRandomNo;
		}

		log("Here is an array crunchifyIntArray[i] ==> " + Arrays.toString(crunchifyIntArray));
		log("\n");

		// Now let's run loop for 10 times to see if my random value is part of int[] crunchifyIntArray
		log("============= Test1: Legacy Java7 Way =============");
		for (int j = 1; j <= 5; j++) {
			crunchifyRandomNo = (7 + (int) (Math.random() * ((95 - 7))));

			if (crunchifyContainsMethod(crunchifyIntArray, crunchifyRandomNo)) {
				log("Matched: " + crunchifyRandomNo + " in array crunchifyIntArray[i]");
			} else {
				log("No Match for: " + crunchifyRandomNo);
			}
		}
		log("\n");

		// this is java8 way to find if Array contains specified value.
		java8IntStreamLongStreamExample(crunchifyIntArray);
		java8ArraysAsListExample(crunchifyIntArray);

	}

	// Java7: Simple Legacy way to check if specified value is there in Array :)
	public static boolean crunchifyContainsMethod(int[] crunchifyIntArray, int matchedValue) {

		for (int isMatched : crunchifyIntArray) {
			if (isMatched == matchedValue) {
				return true;
			}
		}
		return false;
	}

	// Java8: IntStream -> anyMatch() and LongStream.anyMatch() Example
	public static void java8IntStreamLongStreamExample(int[] crunchifyIntArray) {

		// Intstream: A sequence of primitive int-valued elements supporting sequential and parallel aggregate operations.
		// anyMatch() returns whether any elements of this stream match the provided predicate.

		// Now let's run loop for 10 times to see if my random value is part of int[] crunchifyIntArray

		log("============= Test2: Java8 IntStream->anyMatch() Way =============");
		for (int j = 1; j <= 5; j++) {
			int crunchifyRandomNo = (7 + (int) (Math.random() * ((95 - 7))));
			if (IntStream.of(crunchifyIntArray).anyMatch(myValue -> myValue == crunchifyRandomNo)) {
				log("Matched " + crunchifyRandomNo + " in array crunchifyIntArray[i]");
			} else {
				log("No Match for: " + crunchifyRandomNo);
			}
		}
		log("\n");

		long[] crunchifyLongArray = new long[15];
		for (int i = 1; i <= 14; i++) {
			long crunchifyRandomLongNo = (7 + (long) (Math.random() * ((95 - 7))));
			crunchifyLongArray[i] = crunchifyRandomLongNo;
		}
		log("Here is an array crunchifyLongArray[i] ==> " + Arrays.toString(crunchifyLongArray));

		log("\n============= Test3: Java8 LongStream->anyMatch() Way =============");
		for (int j = 1; j <= 5; j++) {
			long crunchifyRandomNo = (7 + (long) (Math.random() * ((95 - 7))));
			if (LongStream.of(crunchifyLongArray).anyMatch(myValue -> myValue == crunchifyRandomNo)) {
				log("Matched " + crunchifyRandomNo + " in array crunchifyLongArray[i]");
			} else {
				log("No Match for: " + crunchifyRandomNo);
			}
		}
		log("\n");

	}

	// Java8: Arrays.asList() contains() and containsAll() Example
	private static void java8ArraysAsListExample(int[] crunchifyIntArray) {
		String[] crunchifyCompany = new String[] { "Facebook", "Twitter", "Google" };

		// Convert String Array to List
		List<String> crunchifyList = Arrays.asList(crunchifyCompany);

		log("============= Test4: Arrays.asList() contains() and containsAll() Example =============");
		if (crunchifyList.contains("Twitter")) {
			log("Matched Found for Twitter");
		}

		if (crunchifyList.contains("Twitter") || crunchifyList.contains("Facebook")) {
			log("Matched Found for Twitter and Facebook");
		}

		// A and B
		if (crunchifyList.containsAll(Arrays.asList("Google", "Facebook"))) {
			log("Matched Found for Google and Facebook");
		}

	}

	// Simple log utility
	private static void log(String string) {
		System.out.println(string);

	}

}

Step-3

Run the program in Eclipse using right click on program and click on Run as Java Application. You should see console result similar to this:

https://crunchify.com/how-to-find-alexa-rank-meta-tag-value-for-all-in-one-webmaster-premium/comment-page-1/#comment-59190


Here is an array crunchifyIntArray[i] ==> [0, 72, 26, 87, 12, 45, 27, 34, 12, 89, 9, 65, 79, 15, 16]


============= Test1: Legacy Java7 Way =============
No Match for: 32
No Match for: 33
Matched 79 in array crunchifyIntArray[i]
No Match for: 40
Matched 12 in array crunchifyIntArray[i]


============= Test2: Java8 IntStream->anyMatch() Way =============
Matched 34 in array crunchifyIntArray[i]
No Match for: 58
No Match for: 62
Matched 27 in array crunchifyIntArray[i]
No Match for: 17


Here is an array crunchifyLongArray[i] ==> [0, 74, 93, 61, 78, 42, 74, 52, 59, 88, 61, 34, 27, 59, 84]

============= Test3: Java8 LongStream->anyMatch() Way =============
No Match for: 15
Matched 84 in array crunchifyLongArray[i]
No Match for: 23
No Match for: 39
No Match for: 69


============= Test4: Arrays.asList() contains() and containsAll() Example =============
Matched Found for Twitter
Matched Found for Twitter and Facebook
Matched Found for Google and Facebook

Let me know if you have any question.

The post 4 Ways to Check if Array Contains a Specific Value in Java8? IntStream and Arrays.asList Tutorial appeared first on Crunchify.

Author: App Shah