How to find duplicate value in an array in java?

Simplest way to find duplicate entries in an array is to add array entries to the TreeSet. As treeset does not support duplicate entries, we can easily find out duplicate entries.

Example

package com.w3schools;
 
import java.util.TreeSet;
 
public class Test {	 
    public static void main(String[] args) {
    	//Create String Array
    	String[] strArray = {"Jai", "Mahesh", "Hemant", "Hemant", "Mahesh"};
 
    	//Create TreeSet Object
    	TreeSet<String> treeSet = new TreeSet<String>();
    	System.out.println("Duplicate Entries: ");
    	for(String string:strArray){
            if(!treeSet.add(string)){
                System.out.println(string);
            }
        }
    }
}

Output

Duplicate Entries: 
Hemant
Mahesh