Check if a value is present in an Array in Java

Given an array, the task is to check whether a certain element is present in this Array or not, in Java.

Examples:

Input: arr[] = [5, 1, 1, 9, 7, 2, 6, 10], key = 7
Output: true

Input: arr[] = [-1, 1, 5, 8], key = -2
Output: false

Below are various ways to do so:

1. Using Linear Search Method:
   In this, the list or array is traversed sequentially and every element is checked.

   Syntax:

   for (int element : arr) {
       if (element == toCheckValue) {
           return true;
       }
   }
   

   Example:

   filter_none

   edit
   close

   play_arrow

   link
   brightness_4
   code

   // Java program to check wether // an element is present in array or not    import java.util.Arrays; import java.util.stream.IntStream;    class GFG {        // Function return true if given element     // found in array     private static void check(int[] arr, int toCheckValue)     {         // check if the specified element         // is present in the array or not         // using Linear Search method         boolean test = false;         for (int element : arr) {             if (element == toCheckValue) {                 test = true;                 break;             }         }            // Print the result         System.out.println("Is " + toCheckValue                            + " present in the array: " + test);     }        public static void main(String[] args)     {            // Get the array         int arr[] = { 5, 1, 1, 9, 7, 2, 6, 10 };            // Get the value to be checked         int toCheckValue = 7;            // Print the array         System.out.println("Array: "                            + Arrays.toString(arr));            // Check if this value is         // present in the array or not         check(arr, toCheckValue);     } }

   chevron_right

   filter_none

   Output:

   Array: [5, 1, 1, 9, 7, 2, 6, 10]
   Is 7 present in the array: true
   

2. Using Binary Search Method:
   In this, search a sorted array by repeatedly dividing the search interval in half. Begin with an interval covering the whole array. If the value of the search key is less than the item in the middle of the interval, narrow the interval to the lower half. Otherwise narrow it to the upper half. Repeatedly check until the value is found or the interval is empty.

   In this example, Arrays.binarySearch() method is used for Binary Search.

   Syntax:

   public static int 
       binarySearch(data_type arr, data_type key)
   

   Example:

   filter_none

   edit
   close

   play_arrow

   link
   brightness_4
   code

   // Java program to check wether // an element is present in array or not    import java.util.Arrays; import java.util.stream.IntStream;    class GFG {        // Function return true if given element     // found in array     private static void check(int[] arr, int toCheckValue)     {         // sort given array         Arrays.sort(arr);            // check if the specified element         // is present in the array or not         // using Binary Search method         int res = Arrays.binarySearch(arr, toCheckValue);            boolean test = res > 0 ? true : false;            // Print the result         System.out.println("Is " + toCheckValue                            + " present in the array: " + test);     }        public static void main(String[] args)     {            // Get the array         int arr[] = { 5, 1, 1, 9, 7, 2, 6, 10 };            // Get the value to be checked         int toCheckValue = 7;            // Print the array         System.out.println("Array: "                            + Arrays.toString(arr));            // Check if this value is         // present in the array or not         check(arr, toCheckValue);     } }

   chevron_right

   filter_none

   Output:

   Array: [5, 1, 1, 9, 7, 2, 6, 10]
   Is 7 present in the array: true
   

3. Using List.contains() Method: List contains() method in Java is used for checking if the specified element exists in the given list or not.

   Syntax:

   
   

   public boolean contains(Object)
   
   where object-element to be searched for.
   

   Example:

   filter_none

   edit
   close

   play_arrow

   link
   brightness_4
   code

   // Java program to check wether // an element is present in array or not    import java.util.Arrays;    class GFG {        // Function return true if given element     // found in array     private static void check(Integer[] arr, int toCheckValue)     {         // check if the specified element         // is present in the array or not         // using contains() method         boolean test             = Arrays.asList(arr)                   .contains(toCheckValue);            // Print the result         System.out.println("Is " + toCheckValue                            + " present in the array: " + test);     }        public static void main(String[] args)     {            // Get the array         Integer arr[] = { 5, 1, 1, 9, 7, 2, 6, 10 };            // Get the value to be checked         int toCheckValue = 7;            // Print the array         System.out.println("Array: "                            + Arrays.toString(arr));            // Check if this value is         // present in the array or not         check(arr, toCheckValue);     } }

   chevron_right

   filter_none

   Output:

   Array: [5, 1, 1, 9, 7, 2, 6, 10]
   Is 7 present in the array: true
   

4. Using Stream.anyMatch() Method:
   Stream anyMatch(Predicate predicate) returns whether any elements of this stream match the provided predicate. It may not evaluate the predicate on all elements if not necessary for determining the result.

   Syntax:

   boolean anyMatch(Predicate<T> predicate)
   
   Where T is the type of the input to the predicate
   and the function returns true if any elements of
   the stream match the provided predicate, 
   otherwise false.
   

   Example 1: Using Stream.of() method to create Stream

   filter_none

   edit
   close

   play_arrow

   link
   brightness_4
   code

   // Java program to check wether // an element is present in array or not    import java.util.Arrays; import java.util.stream.IntStream;    class GFG {        // Function return true if given element     // found in array     private static void check(int[] arr, int toCheckValue)     {         // check if the specified element         // is present in the array or not         // using anyMatch() method         boolean test             = IntStream.of(arr)                   .anyMatch(x -> x == toCheckValue);            // Print the result         System.out.println("Is " + toCheckValue                            + " present in the array: " + test);     }        public static void main(String[] args)     {            // Get the array         int arr[] = { 5, 1, 1, 9, 7, 2, 6, 10 };            // Get the value to be checked         int toCheckValue = 7;            // Print the array         System.out.println("Array: "                            + Arrays.toString(arr));            // Check if this value is         // present in the array or not         check(arr, toCheckValue);     } }

   chevron_right

   filter_none

   Output:

   Array: [5, 1, 1, 9, 7, 2, 6, 10]
   Is 7 present in the array: true
   

   Example 2: Using Arrays.stream() method to create Stream

   filter_none

   edit
   close

   play_arrow

   link
   brightness_4
   code

   // Java program to check wether // an element is present in array or not    import java.util.Arrays; import java.util.stream.IntStream;    class GFG {        // Function return true if given element     // found in array     private static void check(int[] arr, int toCheckValue)     {         // check if the specified element         // is present in the array or not         // using anyMatch() method         boolean test             = IntStream.of(arr)                   .anyMatch(x -> x == toCheckValue);            // Print the result         System.out.println("Is " + toCheckValue                            + " present in the array: " + test);     }        public static void main(String[] args)     {            // Get the array         int arr[] = { 5, 1, 1, 9, 7, 2, 6, 10 };            // Get the value to be checked         int toCheckValue = 7;            // Print the array         System.out.println("Array: "                            + Arrays.toString(arr));            // Check if this value is         // present in the array or not         check(arr, toCheckValue);     } }

   chevron_right

   filter_none

   Output:

   Array: [5, 1, 1, 9, 7, 2, 6, 10]
   Is 7 present in the array: true
   




My Personal Notes arrow_drop_up
Save

Recommended Posts:

• Queries to check whether a given digit is present in the given Range
• Check whether array has all identical elements using Arrays.asList() and HashSet in Java
• Check if the given string of words can be formed from words present in the dictionary
• Java program to read all mobile numbers present in given file
• Check if it is possible to sort the array after rotating it
• Check if all elements of the array are palindrome or not
• Check if elements of an array can be arranged in a Circle with consecutive difference as 1
• Check if the array has an element which is equal to product of remaining elements
• Check if URL is valid or not in Java
• Find all reachable nodes from every node present in a given set
• Check if a File is hidden in Java
• Check for string rotation in Java
• How to check if a key exists in a HashMap in Java
• Check if email address valid or not in Java
• Check if a string contains only alphabets in Java using Regex

---


29AjayKumar
Just another competitive programmer and hard worker

---

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.