How to create TreeSet program in java -

import java.util.*;

class TreeSet_TechSarvam 
{
    public static void main(String args[]) 
    {
        // Creating and adding elements to TreeSet
        TreeSet<String> al = new TreeSet<String>();
        al.add("Rajendra");
        al.add("Raja");
        al.add("Ravi");
        al.add("TechSarvam");

        // Traversing elements using Iterator
        Iterator<String> itr = al.iterator();
        while (itr.hasNext()) 
        {
            System.out.println(itr.next());
        }
    }
}

Step-by-Step Explanation:

1. Importing Required Classes:

import java.util.*;

This line imports necessary classes from the java.util package. It is required to use classes like TreeSet and Iterator.

2. Class Declaration:

class TreeSet_TechSarvam {

The class TreeSet_TechSarvam defines that holds the method main() and holds all the programmatic logics.

3. Main Method:

public static void main(String args[]) {

It’s where your program actually gets to work: that’s a method that Java has created.

4. Creating a TreeSet: TreeSet <String> al = new TreeSet <String>();

A TreeSet is declared and assigned to the variable al. The TreeSet class implements the Set interface, and it stores elements in a sorted order.
The type of elements in the TreeSet is specified as String (so the set will only contain strings).

5. Adding Elements to the TreeSet:

al.add(“Rajendra”);

al.add(“Raja”);

al.add(“Ravi”);

al.add(“TechSarvam”);

The add() method has been used to add elements to the TreeSet. The elements added are “Rajendra”, “Raja”, “Ravi”, and “TechSarvam”.
A TreeSet will automatically sort the elements it holds in ascending order (based on their natural ordering or a Comparator supplied at creation time).
The elements are not kept in the insertion order. “Rajendra”, “Raja”, “Ravi”, and “TechSarvam” will be arranged alphabetically.

6. Creation of an Iterator for Traversal:

Iterator<String> itr = al.iterator();

An Iterator is obtained to iterate over the TreeSet. The iterator() method of the TreeSet is invoked to get an Iterator.

7. Iterate over TreeSet:

while (itr.hasNext()) {

System.out.println(itr.next());

}

The while loop checks for existence of elements in the TreeSet by itr.hasNext() If there are more elements then the loop continues.
The itr.next() fetches the next element from the TreeSet and System.out.println prints to the console.
As TreeSet stores the elements in the sorted order so, while running the loop it will print them in ascending order.

Expected Output:

As it is a sorted set, that is, TreeMap automatically sorts elements in ascending order, so will print them alphabetically:

——————————————————–

Rajendra

Raja

Ravi

TechSarvam