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

## Problem 1: Find the highest stock price

Find the company with the highest stock price.

## Solution:

To find the company with the highest stock price, we will have to first iterate the **HashMap**. We can get the **EntrySet** and then iterate over it. For each entry, we will check if the stock price is more than whatever max value we have. If yes, we will store the company corresponding to this entry in a variable.



# Problem 1: Find the highest stock price

Find the company with the highest stock price.

# Solution:

To find the company with the highest stock price, we will have to first iterate the **HashMap**. We can get the **EntrySet** and then iterate over it. For each entry, we will check if the stock price is more than whatever max value we have. If yes, we will store the company corresponding to this entry in a variable.



Let's look at the solutions for the 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 Solution

Problem 1: Find the highest stock price

Solution: