Program: How to create a TreeSet with a List?

Below example shows how to create TreeSet with other collection. By passing another collection to the TreeSet constructor, you can copy entire collections elements to the TreeSet.

package com.java2novice.treeset;

import java.util.ArrayList;
import java.util.List;
import java.util.TreeSet;

public class MySetWithCollection {
	public static void main(String a[]){
		List<String> li = new ArrayList<String>();
		li.add("one");
		li.add("two");
		li.add("three");
		li.add("four");
		System.out.println("List: "+li);
		//create a treeset with the list
		TreeSet<String> myset = new TreeSet<String>(li);
		System.out.println("Set: "+myset);
	}
}

List: [one, two, three, four]
Set: [four, one, three, two]