Java: Find the duplicate values of an array of integer values

Last update on May 09 2025 12:51:49 (UTC/GMT +8 hours)

12. Find duplicates in integer array

Write a Java program to find duplicate values in an array of integer values.

Pictorial Presentation:

Sample Solution:

Java Code:

// Import the Arrays class from the java.util package.
import java.util.Arrays;

// Define a class named Exercise12.
public class Exercise12 {
    
    // The main method where the program execution starts.
    public static void main(String[] args) {
        // Declare and initialize an integer array 'my_array'.
        int[] my_array = {1, 2, 5, 5, 6, 6, 7, 2};
 
        // Iterate through the elements of the array.
        for (int i = 0; i < my_array.length-1; i++) {
            for (int j = i+1; j < my_array.length; j++) {
                // Check if two elements are equal and not the same element.
                if ((my_array[i] == my_array[j]) && (i != j)) {
                    // If a duplicate is found, print the duplicate element.
                    System.out.println("Duplicate Element : " + my_array[j]);
                }
            }
        }
    }    
}

Sample Output:

Duplicate Element : 2                                                                                         
Duplicate Element : 5                                                                                         
Duplicate Element : 6

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Java program to count the number of duplicate values in an integer array.
• Write a Java program to remove all duplicate values from an integer array.
• Write a Java program to find the most frequently occurring number in an array.
• Write a Java program to return a list of unique numbers from an array by removing duplicates.

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