Add blogpost Java: Check If Array Contains Value or Element

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_posts/array/2021-05-17-java-check-if-array-contains-value-or-element.md

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+---
+layout: post
+title: " Java: Check If Array Contains Value or Element"
+author: gaurav
+categories: [Java, Array]
+description: "In this quick beginner-friendly tutorial, we will see how to check if an array contains a value or an 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,
+1. For String Array
+2. 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.
+
+```java
+Arrays.asList(yourArray).contains(yourValue);
+```
+
+I have given a program below that checks if an array contains a particular string value.
+
+```java
+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 names Array.");
+		}else {
+			System.out.println("String value '"+checkForString+"' is not present in names Array.");
+		}
+
+	} 
+}
+```
+Output:
+```
+String value 'mayur' is present in names Array.
+```
+Check the above code as [GitHub Gist](https://gist.github.com/gauravkukade/1914b7274cd5017364e78d2e6bc5f5bb)
+
+### 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.
+
+```java
+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 names Array.");
+		}else {
+			System.out.println("String value '"+checkForString+"' is not present in names Array.");
+		}		
+	}
+}
+```
+Output:
+```
+String value 'mayur' is present in names Array.
+```
+Check the above code as [GitHub Gist](https://gist.github.com/gauravkukade/3df7496b88b2222ab34d685f5287e725)
+
+## 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.
+
+```java
+/**
+ * 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 contians the value '"+intToCheck+"'.");
+		}else {
+			System.out.println("The numbers array does not contian the value '"+intToCheck+"'.");
+		}
+	}
+}
+```
+Output:
+```
+The numbers array contians the value '5'.
+```
+Check the above code as [GitHub Gist](https://gist.github.com/gauravkukade/7cf0ba43baccbc9e828277c19f5c14a7)
+
+### Java 8 Update 
+
+
+In Java 8, we have Streams API. We can use it 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.
+
+```java
+/**
+ * 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 contians the value '"+intToCheck+"'.");
+		}else {
+			System.out.println("The numbers array does not contian the value '"+intToCheck+"'.");
+		}
+        }
+}
+```
+Output:
+```java
+The numbers array contians the value '2'.
+```
+Check the above code as [GitHub Gist](https://gist.github.com/gauravkukade/e2f15eea99ddb869b406ba90f439e419)
+
+## Check if an array contains a value using the 'Apache Commons Lang' 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 'Apache Commons Lang library'
+
+Since Apache Commons Lang library' is the most commonly used library, there are chances that your project may already have it.
+```
+<!-- 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.
+
+```java
+import org.apache.commons.lang3.ArrayUtils;
+
+/**
+ * A java program to check if an array contains a value suing the 
+ * Apache common lang library's ArrayUtils.contains() method
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayUtilsExample {
+
+	public static void main(String[] args) {
+
+		// check 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 contians the value '"+intToCheck+"'.");
+		}else {
+			System.out.println("The numbers array does not contian the value '"+intToCheck+"'.");
+		}
+
+		// check 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 names array.");
+		}else {
+			System.out.println("String value '"+stringToCheck+"' is not present in names array.");
+		}	
+	}
+}
+```
+Output:
+```
+The numbers array contians the '8' value.
+String value 'gaurav' is present in names array.
+```
+Check the above code as [GitHub Gist](https://gist.github.com/gauravkukade/a93dd0faec3bebd75fa9833d5089d482)
+
+## 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.
+```java
+Arrays.asList(yourArray).contains(yourValue);
+```
+From Java 8 we can use Stream API to check if an array contains a value. 
+```java
+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 a equals condition in the loop.
+
+```java
+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`  value respectively.
+```java
+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 'Apache common Lang' Library
+
+You can use the `ArrayUtils.contains()` method of Apache common Lang Library to check if an array contains a value.
+
+```java
+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 check if an array contains a value or element using java programming language, please comment below.
+
+You can check my YouTube channel [here](https://www.youtube.com/channel/UCl31HHUdQbSHOQfc9L-wo3w)
+
+### Related Articles
+
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+
+-   [How To Convert An Integer To String In Java](https://coderolls.com/convert-int-to-string/)
+
+-   [How to convert String to Integer in Java](https://coderolls.com/convert-string-to-int/)
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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/)
+
+