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Merge pull request#32 from coderolls/blogpost/check-if-array-contains-a-value-or-element
Add blogpost Java: Check If Array Contains Value or Element
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‎_layouts/default.html

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<!-- Site Title
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<h1class="sitetitle"><ahref="https://coderolls.com/">{{ site.name }}</a></h1>
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<h1class="sitetitle"><ahref="{{ site.baseurl }}/">{{ site.name }}</a></h1>
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---
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layout:post
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title:" Java: Check If Array Contains Value or Element"
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author:gaurav
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categories:[Java, Array]
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description:"In this quick beginner-friendly tutorial, we will see how to check if an array contains a value or an element."
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---
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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.
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We can check if an element or value is present or not in two types of arrays,
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1. For String Array
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2. For Primitive Array
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##1. For String Array.
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For String Array, we can check if an array contains a particular string value using the`contains()` method.
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The code snippet is given below.
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```java
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Arrays.asList(yourArray).contains(yourValue);
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```
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I have given a program below that checks if an array contains a particular string value.
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```java
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importjava.util.Arrays;
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/**
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* A Java program that checks if a String array contains a particular string value
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*
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*@author Gaurav Kukade
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*
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*/
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publicclassCheckInStringArray {
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publicstaticvoidmain(String[]args) {
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String [] names= {"gaurav","shubham","krishna","mayur"};
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String checkForString="mayur";
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boolean stringPresentInArray=Arrays.asList(names).contains(checkForString);
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if(stringPresentInArray) {
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System.out.println("String value '"+checkForString+"' is present in names Array.");
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}else {
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System.out.println("String value '"+checkForString+"' is not present in names Array.");
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}
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}
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}
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```
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Output:
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```
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String value 'mayur' is present in names Array.
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```
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Check the above code as[GitHub Gist](https://gist.github.com/gauravkukade/1914b7274cd5017364e78d2e6bc5f5bb)
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###Java 8 Update
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In Java 8, we have Streams API. We can use it to check if a String array contains a particular String value.
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I have given a complete program below.
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```java
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importjava.util.Arrays;
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/**
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* A Java program that checks if a String array contains a particular string value
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* using the Java 8 Stream API.
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*
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*@author Gaurav Kukade
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*
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*/
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publicclassCheckInStringArrayUsingStream {
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publicstaticvoidmain(String[]args) {
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String [] names= {"gaurav","shubham","krishna","mayur"};
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String checkForString="mayur";
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boolean stringPresentInArray=Arrays.stream(names).anyMatch(checkForString::equals);;
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if(stringPresentInArray) {
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System.out.println("String value '"+checkForString+"' is present in names Array.");
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}else {
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System.out.println("String value '"+checkForString+"' is not present in names Array.");
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}
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}
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}
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```
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Output:
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```
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String value 'mayur' is present in names Array.
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```
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Check the above code as[GitHub Gist](https://gist.github.com/gauravkukade/3df7496b88b2222ab34d685f5287e725)
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##2. For Primitive Array
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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)
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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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```java
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/**
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* A Java program to check if a primitive array contains a primitive value
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*
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*@author Gaurav Kukade at coderolls.com
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*
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*/
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publicclassCheckInPrimitiveArray {
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publicstaticvoidmain(String[]args) {
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int[] numbers= {1,2,3,4,5,6,7};
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int intToCheck=5;
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boolean contains=false;
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for(int number: numbers) {
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// check if number and intToCheck are equal,
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// if yes make contains as true and break the loop
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if(number== intToCheck) {
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contains=true;
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break;
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}
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}
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if(contains){
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System.out.println("The numbers array contians the value '"+intToCheck+"'.");
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}else {
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System.out.println("The numbers array does not contian the value '"+intToCheck+"'.");
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}
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}
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}
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```
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Output:
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```
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The numbers array contians the value '5'.
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```
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Check the above code as[GitHub Gist](https://gist.github.com/gauravkukade/7cf0ba43baccbc9e828277c19f5c14a7)
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###Java 8 Update
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In Java 8, we have Streams API. We can use it check if a primitive array (int[], long[], char[], etc) contains a primitive value.
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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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I have given a complete program below.
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```java
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/**
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* A Java program to check if a primitive array contains a primitive value
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* using the Java 8 Stream API
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*
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*@author Gaurav Kukade at coderolls.com
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*
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*/
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publicclassCheckInPrimitiveArrayUsingStream {
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publicstaticvoidmain(String[]args) {
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int[] numbers= {1,2,3,4,5,6,7};
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int intToCheck=2;
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boolean contains=IntStream.of(numbers).anyMatch(x-> x== intToCheck);
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if(contains){
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System.out.println("The numbers array contians the value '"+intToCheck+"'.");
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}else {
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System.out.println("The numbers array does not contian the value '"+intToCheck+"'.");
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}
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}
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}
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```
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Output:
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```java
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The numbers array contians the value'2'.
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```
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Check the above code as[GitHub Gist](https://gist.github.com/gauravkukade/e2f15eea99ddb869b406ba90f439e419)
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##Check if an array contains a value using the 'Apache Commons Lang' library
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Apache Commons Lang library has useful functions to manipulate the array.
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It is not recommended to add a new dependency just to check if your array contains a value.
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You can go with Apache Commons Lang library to perform such a simple operation if,
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- If your project is not using Java 8
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- it already has a dependency on the 'Apache Commons Lang library'
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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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```
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<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
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<dependency>
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<groupId>org.apache.commons</groupId>
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<artifactId>commons-lang3</artifactId>
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<version>3.11</version>
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</dependency>
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```
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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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```java
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importorg.apache.commons.lang3.ArrayUtils;
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/**
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* A java program to check if an array contains a value suing the
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* Apache common lang library's ArrayUtils.contains() method
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*
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*@author Gaurav Kukade at coderolls.com
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*
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*/
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publicclassArrayUtilsExample {
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publicstaticvoidmain(String[]args) {
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// check in primitive ( int[]) array
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int[] numbers= {1,2,3,4,5,6,7,8,9};
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int intToCheck=8;
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boolean containsInt=ArrayUtils.contains(numbers, intToCheck);
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if(containsInt){
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System.out.println("The numbers array contians the value '"+intToCheck+"'.");
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}else {
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System.out.println("The numbers array does not contian the value '"+intToCheck+"'.");
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}
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// check in String array
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String[] names= {"gaurav","shubham","krishna","mayur"};
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String stringToCheck="gaurav";
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boolean containsString=ArrayUtils.contains(names, stringToCheck);
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if(containsString) {
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System.out.println("String value '"+stringToCheck+"' is present in names array.");
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}else {
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System.out.println("String value '"+stringToCheck+"' is not present in names array.");
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}
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}
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}
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```
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Output:
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```
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The numbers array contians the '8' value.
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String value 'gaurav' is present in names array.
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```
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Check the above code as[GitHub Gist](https://gist.github.com/gauravkukade/a93dd0faec3bebd75fa9833d5089d482)
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##Conclusion
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We have seen all the possible ways to check if an array contains a value or not in Java.
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We will summarize these ways below
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###1. For String array
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We can use the following code snippet.
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```java
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Arrays.asList(yourArray).contains(yourValue);
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```
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From Java 8 we can use Stream API to check if an array contains a value.
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```java
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String [] names= {"gaurav","shubham","krishna","mayur"};
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boolean stringPresentInArray=Arrays.stream(names).anyMatch("mayur"::equals);;
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```
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###2. For Primitive Array
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To check if a primitive array contains a value, we can use the simple for loop and add a equals condition in the loop.
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```java
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int[] numbers= {1,2,3,4,5,6,7};
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boolean contains=false;
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for(int number: numbers) {
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if(number==4) {
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contains=true;
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break;
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}
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}
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```
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From Java 8, we can use classes like`IntStream`,`DoubleStream` or`LongStream` to check whether an array contains`int`,`double` or`long` value respectively.
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```java
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int[] numbers= {1,2,3,4,5,6,7};
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boolean contains=IntStream.of(numbers).anyMatch(x-> x==3);
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```
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###Check using the`ArrayUtils.contains()` method of 'Apache common Lang' Library
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You can use the`ArrayUtils.contains()` method of Apache common Lang Library to check if an array contains a value.
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```java
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int[] numbers= {1,2,3,4,5,6,7,8,9};
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boolean containsInt=ArrayUtils.contains(numbers,7);
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String[] names= {"gaurav","shubham","krishna","mayur"};
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boolean containsString=ArrayUtils.contains(names,"gaurav");
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```
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I hope this article will help you to check if an array contains a value in Java.
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If you have any other ways to check check if an array contains a value or element using java programming language, please comment below.
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You can check my YouTube channel[here](https://www.youtube.com/channel/UCl31HHUdQbSHOQfc9L-wo3w)
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###Related Articles
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-[How To Get Current Timestamp In Java?](https://coderolls.com/how-to-get-current-timestamps-in-java/)
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-[How To Convert An Integer To String In Java](https://coderolls.com/convert-int-to-string/)
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-[How to convert String to Integer in Java](https://coderolls.com/convert-string-to-int/)
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-[How To Convert StringBuilder To String In Java?](https://coderolls.com/convert-stringbuilder-to-string-in-java/)
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-[How Do I Compare Strings In Java](https://coderolls.com/compare-strings-in-java/)
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-[How To Reverse A String In Java (5 ways)](https://coderolls.com/reverse-a-string-in-java/)
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