How to Print HashSet Elements in Java?

In HashSet, duplicates are not allowed. If we are trying to insert duplicates then we won't get any compile-time or runtime error and the add() method simply returns false.

We can use 2 ways to print HashSet elements:

1. Using the iterator() method to traverse the set elements and printing it.
2. Directly printing it using a reference variable.

Method 1: By using Cursor which is Iterator.

• If we want to get objects one by one from the collection then we should go for the cursor.
• We can apply the Iterator concept for any Collection Object and hence it is a Universal Cursor.
• By using Iterator we can perform both read and remove operations.
• We can create an Iterator object by using the iterator method of Collection Interface.

public Iterator iterator();   //  Iterator method of Collection Interface.

• Creating an iterator object

Iterator itr = c.iterator();  // where c is any Collection Object like ArrayList,HashSet etc.

Example:

null
2
3
5
6

Method 2: We can directly print HashSet elements by using the HashSet object reference variable. It will print the complete HashSet object.

Note: If we do not know the hash code, so you can't decide the order of insertion.

Example: