/*find if the array has duplicate by using brute force*/ public boolean bruteforce(String[] arr) { for (int i = 0; i < arr.length; i++) { for (int j = 0; j < arr.length; j++) { if (arr[i].equals(arr[j]) && i != j) return true; } } return false; } /*It will return true if the array has duplicates*/ public boolean hasDuplicates(String[] input){ List inputList = Arrays.asList(input); Set inputSet = new HashSet(inputList); if(inputSet.size()< inputList.size()) return true; return false; } /*This method will return the suplicate value(if present), else a blank string.*/ public String checkDuplicateUsingAdd(String[] input) { Set inputSet = new HashSet(); for (String str : input) { if (!inputSet.add(str)) return str; } return ""; }