Scanner scanner = new Scanner(System.in); strings = new String[6]; for(int i = 0; i<6;i++){ strings[i] = scanner.nextLine(); } for(int i= 0;i<strings.length;i++){ if(strings[i]!=null) { for (int j = i + 1; j < strings.length; j++) { if ((strings[i]!=null)&&(strings[j] != null) && (strings[i].equals(strings[j]))) { strings[i] = null; strings[j] = null; } } } } for (int i = 0; i < strings.length; i++) { System.out.print(strings[i] + ", "); }