Java Program to Check if An Array Contains a Given Value

Example 1: Check if Int Array contains a given value

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

    int[] num = {1, 2, 3, 4, 5};
    int toFind = 3;
    boolean found = false;

    for (int n : num) {
      if (n == toFind) {
        found = true;
        break;
      }
    }
    
    if(found)
      System.out.println(toFind + " is found.");
    else
      System.out.println(toFind + " is not found.");
  }
}

Output

3 is found.

In the above program, we have an array of integers stored in variable num. Likewise, the number to be found is stored in toFind.

Now, we use a for-each loop to iterate through all elements of num and check individually if toFind is equal to n or not.

If yes, we set found to true and break from the loop. If not, we move to the next iteration.

Example 2: Check if an array contains the given value using Stream

import java.util.stream.IntStream;

class Main {
  public static void main(String[] args) {
    
    int[] num = {1, 2, 3, 4, 5};
    int toFind = 7;

    boolean found = IntStream.of(num).anyMatch(n -> n == toFind);

    if(found)
      System.out.println(toFind + " is found.");
    else
      System.out.println(toFind + " is not found.");
      
  }
}

Output

7 is not found.

In the above program, instead of using a for-each loop, we convert the array to an IntStream and use its anyMatch() method.

anyMatch() method takes a predicate, an expression, or a function that returns a boolean value. In our case, the predicate compares each element n in the stream to toFind and returns true or false.

If any of the element n returns true, found is set to true as well.

Example 3: Check if an array contains a given value for non-primitive types

import java.util.Arrays;

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

    String[] strings = {"One","Two","Three","Four","Five"};
    String toFind= "Four";

    boolean found = Arrays.stream(strings).anyMatch(t -> t.equals(toFind));

    if(found)
      System.out.println(toFind + " is found.");
    else
      System.out.println(toFind + " is not found.");
  }
}

Output

Four is found.

In the above program, we've used a non-primitive data type String and used Arrays's stream() method to first convert it to a stream and anyMatch() to check if the array contains the given value toFind.