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

We are given a HashMap which contains stock data.

## Problem 1: Find the highest stock price

Find the company with the highest stock price.

## Problem 2: Find the average stock price

 Find the average stock price of all the companies
 
## Problem 3: Remove companies with stock price below 50

Remove all the companies that have a stock price of fewer than 50 dollars.



We are given a HashMap which contains stock data.

# Problem 1: Find the highest stock price

Find the company with the highest stock price.

# Problem 2: Find the average stock price

 Find the average stock price of all the companies
 
# Problem 3: Remove companies with stock price below 50

Remove all the companies that have a stock price of fewer than 50 dollars.



Let's solve some HashMap practice problems.

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

HashMap: Exercise

Problem 1: Find the highest stock price

Problem 2: Find the average stock price

Problem 3: Remove companies with stock price below 50