Gain insights into Java Collections Framework. Delve into lists, sets, and hashmaps. Learn about data modification, sorting, thread-safety, and internal workings for efficient usage.

Collection is one of the most important topics for Java programming. Without the proper knowledge of every collection type in Java, it becomes difficult for you to decide which option to pick in a particular scenario.

This course will give you a great understanding of all collection types available in the Collections Framework like lists, linked lists, sets, and hashmaps. 

After completing this course, you will know how data can be modified within a collection, how to sort a collection, and how it can be made thread-safe. You will also cover the internal working of each Java collection so you can work with them more efficiently.

Collections in Java

# Iterating a HashSet

Below are the different methods to iterate over a HashSet.

# Using `for` loop
A **HashSet** can be easily iterated using an enhanced `for` loop as shown below.

import java.util.HashSet;
import java.util.Set;

public class HashSetDemo {
	public static void main(String args[]) {
		Set<Integer> set = new HashSet<>();

		set.add(23);
		set.add(34);
		set.add(56);

		for(int i : set) {
			System.out.println(i);
		}
	}
}


# Using `Iterator`
HashSet can also be iterated using an iterator as shown in the below example.

Let's look at different ways to iterate a HashSet.

Let's Begin

Lists in Java

LinkedList in Java

CopyOnWriteArrayList in Java

Sets in Java

TreeSet in Java

HashMap In Java

TreeMap in Java

LinkedHashMap in Java

Additional Map Implementations

Arrays Class

Collections Class

HashSet: Iteration and Sorting

Iterating a HashSet

Using `for` loop

HashSet: Iteration and Sorting

Iterating a HashSet

Using for loop

Using `for` loop