String remove duplicate method in java code example

Example 1: 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();

Example 2: java remove duplicates

import java.util.*;

public class RemoveDuplicatesFromArrayList {

    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(1,2,2,2,3,5);

        System.out.println(numbers);

        Set<Integer> hashSet = new LinkedHashSet(numbers);
        ArrayList<Integer> removedDuplicates = new ArrayList(hashSet);

        System.out.println(removedDuplicates);
    }
}

Example 3: java remove duplicates

public static <T> ArrayList<T> removeDuplicates(ArrayList<T> list){
  Set<T> set = new LinkedHashSet<>(list);
  return new ArrayList<T>(set);
}

Example 4: array remove duplicate in java

List<Integer>numbers = Arrays.asList(1,2,2,2,3,5);
System.out.println(numbers);

Set<Integer> hashSet = new LinkedHashSet(numbers);
ArrayList<Integer> removedDuplicates = new ArrayList(hashSet);
System.out.println(removedDuplicates);

Example 5: String remove duplicate method in java

public static void main(String[] args) {

        String result = removeDup("AAABBBCCC");
        System.out.println(result); // ABC

public static  String  removeDup( String  str) {
        String result = "";
        for (int i = 0; i < str.length(); i++)
            if (!result.contains("" + str.charAt(i)))
                result += "" + str.charAt(i);
        return result;
    }
}