Find Duplicate In Array Java

 package aRray;

import java.util.*;

public class practicalArray {

public static int findDuplicate(int arr[], int size) {

for(int i = 0 ; i < size; i++) {

for(int j = i+1; j < size; j++) {

if(arr[i] == arr[j]) {

return arr[i];

}

}

}

return -1;

}

public static void main(String [] args) {

Scanner scan = new Scanner(System.in);

int size = scan.nextInt();

int [] arr = new int[size];

for(int i = 0; i < size; i++) {

arr[i] = scan.nextInt();

}

int result = findDuplicate(arr,size);

System.out.println(result);

//print process

}

}