java program to remove duplicate words in a string
String fullString = "lol lol"; String[] words = fullString.split("\\W+"); StringBuilder stringBuilder = new StringBuilder(); Set<String> wordsHashSet = new HashSet<>(); for (String word : words) { if (wordsHashSet.contains(word.toLowerCase())) continue; wordsHashSet.add(word.toLowerCase()); stringBuilder.append(word).append(" "); } String nonDuplicateString = stringBuilder.toString().trim();