Java: Check If Array Contains Value or Element
In this quick beginner-friendly tutorial, we will see how to check if an array contains a value or an element using the Java Programming Language.
We can check if an element or value is present or not in two types of arrays,
- For String Array
- For Primitive Array
1. For String Array.
For String Array, we can check if an array contains a particular string value using the contains() method.
The code snippet is given below.
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Arrays.asList(yourArray).contains(yourValue);
I have given a program below that checks if an array contains a particular string value.
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import java.util.Arrays;
/**
* A Java program that checks if a String array contains a particular string value
*
* @author Gaurav Kukade
*
*/
public class CheckInStringArray {
public static void main(String[] args) {
String [] names = {"gaurav", "shubham", "Krishna", "mayur"};
String checkForString = "mayur";
boolean stringPresentInArray = Arrays.asList(names).contains(checkForString);
if(stringPresentInArray) {
System.out.println("String value '"+checkForString+"' is present in the names Array.");
}else {
System.out.println("String value '"+checkForString+"' is not present in the names Array.");
}
}
}
Output:
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String value 'mayur' is present in the names Array.
Check the above code as GitHub Gist
Java 8 Update
In Java 8, we have Streams API. We can use it to check if a String array contains a particular String value.
I have given a complete program below.
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import java.util.Arrays;
/**
* A Java program that checks if a String array contains a particular string value
* using the Java 8 Stream API.
*
* @author Gaurav Kukade
*
*/
public class CheckInStringArrayUsingStream {
public static void main(String[] args) {
String [] names = {"gaurav", "shubham", "krishna", "mayur"};
String checkForString = "mayur";
boolean stringPresentInArray = Arrays.stream(names).anyMatch(checkForString::equals);;
if(stringPresentInArray) {
System.out.println("String value '"+checkForString+"' is present in the names Array.");
}else {
System.out.println("String value '"+checkForString+"' is not present in the names Array.");
}
}
}
Output:
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String value 'mayur' is present in the names Array.
Check the above code as GitHub Gist
2. For Primitive Array
When we have to check if a primitive array (int[], long[], char[], etc) contains any particular primitive values, we have to loop over the array and check the condition manually. ( Till Java 7)
I have given a program below that shows how to check if a primitive array (int[], long[], char[], etc) contains a primitive value or not.
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/**
* A Java program to check if a primitive array contains a primitive value
*
* @author Gaurav Kukade at coderolls.com
*
*/
public class CheckInPrimitiveArray {
public static void main(String[] args) {
int[] numbers = {1, 2, 3, 4, 5, 6, 7};
int intToCheck = 5;
boolean contains = false;
for(int number: numbers) {
// check if number and intToCheck are equal,
// if yes make contains as true and break the loop
if(number == intToCheck) {
contains = true;
break;
}
}
if(contains){
System.out.println("The numbers array contains the value '"+intToCheck+"'.");
}else {
System.out.println("The numbers array does not contain the value '"+intToCheck+"'.");
}
}
}
Output:
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The numbers array contains the value '5'.
Check the above code as GitHub Gist
Java 8 Update
In Java 8, we have Streams API. We can use it to check if a primitive array (int[], long[], char[], etc) contains a primitive value.
We can use classes like IntStream, DoubleStream or LongStream to check whether an array contains int, double or long values respectively.
I have given a complete program below.
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/**
* A Java program to check if a primitive array contains a primitive value
* using the Java 8 Stream API
*
* @author Gaurav Kukade at coderolls.com
*
*/
public class CheckInPrimitiveArrayUsingStream {
public static void main(String[] args) {
int[] numbers = {1, 2, 3, 4, 5, 6, 7};
int intToCheck = 2;
boolean contains = IntStream.of(numbers).anyMatch(x -> x == intToCheck);
if(contains){
System.out.println("The numbers array contains the value '"+intToCheck+"'.");
}else {
System.out.println("The numbers array does not contain the value '"+intToCheck+"'.");
}
}
}
Output:
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The numbers array contains the value '2'.
Check the above code as GitHub Gist
Check if an array contains a value using the āApache Commons Langā library
Apache Commons Lang library has useful functions to manipulate the array.
It is not recommended to add a new dependency just to check if your array contains a value.
You can go with Apache Commons Lang library to perform such a simple operation if,
- If your project is not using Java 8
- it already has a dependency on the āApache Commons Lang libraryā
Since Apache Commons Lang library is the most commonly used library, there are chances that your project may already have it.
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<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.11</version>
</dependency>
If you want to check if an array contains a value using the Apache Commons Lang Library utility functions, you can do it as given below.
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import org.apache.commons.lang3.ArrayUtils;
/**
* A Java program to check if an array contains a value using the
* Apache common lang library's ArrayUtils.contains() method
*
* @author Gaurav Kukade at coderolls.com
*
*/
public class ArrayUtilsExample {
public static void main(String[] args) {
// search in primitive ( int[]) array
int[] numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9};
int intToCheck = 8;
boolean containsInt = ArrayUtils.contains(numbers, intToCheck);
if(containsInt){
System.out.println("The numbers array contains the value '"+intToCheck+"'.");
}else {
System.out.println("The numbers array does not contain the value '"+intToCheck+"'.");
}
// search in String array
String[] names = {"gaurav", "shubham", "krishna", "mayur"};
String stringToCheck = "gaurav";
boolean containsString = ArrayUtils.contains(names, stringToCheck);
if(containsString) {
System.out.println("String value '"+stringToCheck+"' is present in the names array.");
}else {
System.out.println("String value '"+stringToCheck+"' is not present in the names array.");
}
}
}
Output:
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The numbers array contains the '8' value.
String value 'gaurav' is present in the names array.
Check the above code as GitHub Gist
Conclusion
We have seen all the possible ways to check if an array contains a value or not in Java.
We will summarize these ways below
1. For String array
We can use the following code snippet.
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Arrays.asList(yourArray).contains(yourValue);
From Java 8 we can use Stream API to check if an array contains a value.
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String [] names = {"gaurav", "shubham", "krishna", "mayur"};
boolean stringPresentInArray = Arrays.stream(names).anyMatch("mayur"::equals);;
2. For Primitive Array
To check if a primitive array contains a value, we can use the simple for loop and add an equal condition in the loop.
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int[] numbers = {1, 2, 3, 4, 5, 6, 7};
boolean contains = false;
for(int number: numbers) {
if(number == 4) {
contains = true;
break;
}
}
From Java 8, we can use classes like IntStream, DoubleStream or LongStream to check whether an array contains int, double or long values respectively.
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int[] numbers = {1, 2, 3, 4, 5, 6, 7};
boolean contains = IntStream.of(numbers).anyMatch(x -> x == 3);
Check using the ArrayUtils.contains() method of āApache common Langā Library
You can use the ArrayUtils.contains() method of Apache common Lang Library to check if an array contains a value.
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int[] numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9};
boolean containsInt = ArrayUtils.contains(numbers, 7);
String[] names = {"gaurav", "shubham", "krishna", "mayur"};
boolean containsString = ArrayUtils.contains(names, "gaurav");
I hope this article will help you to check if an array contains a value in Java.
If you have any other ways to check if an array contains a value or element using java programming language, please comment below.
You can check my YouTube channel here
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