JAVA

how to remove duplcates elements from arraylist

// Java program to remove duplicates from ArrayList
  
import java.util.*;
  
public class GFG {
  
    // Function to remove duplicates from an ArrayList
    public static <T> ArrayList<T> removeDuplicates(ArrayList<T> list)
    {
  
        // Create a new ArrayList
        ArrayList<T> newList = new ArrayList<T>();
  
        // Traverse through the first list
        for (T element : list) {
  
            // If this element is not present in newList
            // then add it
            if (!newList.contains(element)) {
  
                newList.add(element);
            }
        }
  
        // return the new list
        return newList;
    }
  
    // Driver code
    public static void main(String args[])
    {
  
        // Get the ArrayList with duplicate values
        ArrayList<Integer>
            list = new ArrayList<>(
                Arrays
                    .asList(1, 10, 1, 2, 2, 3, 3, 10, 3, 4, 5, 5));
  
        // Print the Arraylist
        System.out.println("ArrayList with duplicates: "
                           + list);
  
        // Remove duplicates
        ArrayList<Integer>
            newList = removeDuplicates(list);
  
        // Print the ArrayList with duplicates removed
        System.out.println("ArrayList with duplicates removed: "
                           + newList);
    }
}

Program to remove duplicates in an ArrayList

import java.util.ArrayList;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;

public class ArrayDuplicate {
    public static void main(String args[]) {

List<Integer> num = new ArrayList<Integer>();
num.add(1);
num.add(2);
num.add(3);
num.add(4);
num.add(5);
num.add(6);
num.add(3);
num.add(4);
num.add(5);
num.add(6);

System.out.println("Your list of elements in ArrayList : " + num);
Set<Integer> primesWithoutDuplicates = new LinkedHashSet<Integer>(num);
num.clear();
num.addAll(primesWithoutDuplicates);
System.out.println("list of original numbers without duplication: " + num);

}
}

remove duplicates from list java

Set<String> set = new HashSet<>(yourList);
yourList.clear();
yourList.addAll(set);

remove duplicates from list java

 ArrayList<Object> withDuplicateValues;
 HashSet<Object> withUniqueValue = new HashSet<>(withDuplicateValues);
 
 withDuplicateValues.clear();
 withDuplicateValues.addAll(withUniqueValue);

list remove duplicates Java

// remove duplicates with HashSet
Set<Song> songSet = new HashSet<>(songList);
System.out.println("6: " + songSet);

// TreeSet, remove duplicates and keep it sorted
Set<Song> songTreeSet = new TreeSet<>(songList);
System.out.println("7: " + songTreeSet);
// TreeSet can accept Comparator, pass it in its constructor
Set<Song> songTreeSetComparator = new TreeSet<>((o1, o2) -> o1.getBpm() - o2.getBpm());
songTreeSetComparator.addAll(songList);
System.out.println("8: (sort by BPM)" + songTreeSetComparator);