Removing Duplicate Elements From ArrayList Using HashSet

//PENDING QUESTIONS:
//13)How to find largest number less than a given number and without a given digit?
//15) How to find continuous sub array whose sum is equal to given number?

package practice;

import java.util.ArrayList;
import java.util.HashSet;

public class rough
{
	public static void main(String args[]) 
	{
		ArrayList<String> AL = new ArrayList<>();
		
		AL.add("paras");
		AL.add("bhatt");
		AL.add("bhatt");
		AL.add("charu");
		AL.add("paras");
		AL.add("youtube");
		
		System.out.println("Before HashSet:\n"+AL);
		HashSet<String> set = new HashSet<>(AL);
		
//		The important points about Java HashSet class are:

//			HashSet stores the elements by using a mechanism called hashing.
//			HashSet contains unique elements only.
//			HashSet allows null value.
//			HashSet class is non synchronized.
//			HashSet doesn't maintain the insertion order. Here, elements are inserted on the basis of their hashcode.
//			HashSet is the best approach for search operations.
//			The initial default capacity of HashSet is 16, and the load factor is 0.75.
			
		ArrayList<String> ALD = new ArrayList<>(set);
		System.out.println("After HashSet:\n"+ALD);
	}
}