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 an ArrayList that contains `Employee` objects. We need to print the following details:

## Problem 1: Find employees aged over 50
All the employee names whose age is more than 50.

## Problem  2: Find employees from the USA
Remove all the Employees from the List who reside in the USA.

## Problem 3: Sort employees by country
Sort all the employees by country name.

We are given an ArrayList that contains `Employee` objects. We need to print the following details:

# Problem 1: Find employees aged over 50
All the employee names whose age is more than 50.

# Problem  2: Find employees from the USA
Remove all the Employees from the List who reside in the USA.

# Problem 3: Sort employees by country
Sort all the employees by country name.

Let's solve some ArrayList 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

ArrayList: Exercise

Problem 1: Find employees aged over 50

Problem 2: Find employees from the USA

Problem 3: Sort employees by country