Check If All Elements in An Array Are Equal Java

Check if all elements in an Array are Equal Java | Here, the problem is to check whether all the elements in an array are equal or not. As we just need to check the elements in the given array, therefore there is no need to compare between two or more arrays. Hence to solve this problem we just need one array of any type.

Let us see some example to check if all elements in an array are equal Java:-

1) array1[ ] = {1,1,1,1}
Yes, all array elements are equal.

2) array2[ ] = {1,2,3,4}
No, the array elements are not equal.

3) array3[ ] = {“apple”, “apple”}
Yes, the elements of the string array are equal.

4) double array4[ ] = {1223345.5, 1289067.7, 1234678.6}
No, the given double array elements are not equal.

Check If all Elements in an Array are Equal Java using HashSet

Set only store unique elements. For example, if we try to store number 123 any number of times then it will store them only once. Hence the idea is to create a set and store all elements of the given array in the set.

After storing in the set, if the set contains only 1 element then all arrays was equal else if the set contains different elements.

Check If all Elements in an Array are Equal Java by Set

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

public class Main {
   public static void main(String[] args) {
      Integer[] array = { 10, 10, 10, 10 };
      Set<Integer> set = new HashSet<>(Arrays.asList(array));
      if (set.size() == 1) {
         System.out.println("All elements of array are same");
      } else {
         System.out.println("All elements of array are not same");
      }
   }
}

Output:-

All elements of array are same

Check If all Elements in an Array are Equal Java using Set & Stream

import java.util.Arrays;
import java.util.Set;
import java.util.stream.Collectors;

public class Main {
   public static void main(String[] args) {
      int[] array = { 10, 10, 10, 10, 10 };

      Set<Integer> result = 
        Arrays.stream(array).boxed().collect(Collectors.toSet());
      boolean checkequal = result.size() == 1;
      System.out.println(checkequal);
   }
}

Output:-

true

Check If all Elements in an Array are Equal Java by using Stream.distinct() method

import java.util.Arrays;

public class Main {
   public static void main(String[] args) {
      int[] array = { 10, 10, 10, 10, 10 };
      boolean checkequal = 
        Arrays.stream(array).distinct().count() == 1;
      System.out.println(checkequal);
   }
}

Output:-

true

Check If all Elements in an Array are Equal Java by using Stream.allMatch() method

import java.util.Arrays;

public class Main {
   public static void main(String[] args) {
      int[] array = { 1, 1, 1, 1, 1 };
      boolean checkequal = 
            array.length == 1 || 
            Arrays.stream(array).allMatch(t -> t == array[0]);
      System.out.println(checkequal);
   }
}

Output:-

true

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