Java for Programmers

Collections 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.

Java Collections

## Inserting into an ArrayList

There are four ways to add elements in an **ArrayList**:

### Inserting a single element at the end
To add a single element at the end of the List, the `add(E e)` method can be used, where `E` refers to any type of object. This method will check if there is sufficient capacity in the **ArrayList**. If the **ArrayList** is full, then it will resize it and insert the element at the end.


# Inserting into an ArrayList

There are four ways to add elements in an **ArrayList**:

## Inserting a single element at the end
To add a single element at the end of the List, the `add(E e)` method can be used, where `E` refers to any type of object. This method will check if there is sufficient capacity in the **ArrayList**. If the **ArrayList** is full, then it will resize it and insert the element at the end.


Let's see how we insert and retrieve elements from an ArrayList.


ArrayList: Inserting and Retrieving Elements

Let's see how we insert and retrieve elements from an ArrayList.

Introduction

ArrayList

LinkedList

CopyOnWriteArrayList

HashSet

TreeSet

HashMap

TreeMap

LinkedHashMap

Additional Map Implmentations

Arrays

Collections class

ArrayList: Inserting and Retrieving Elements

Inserting into an ArrayList

Inserting a single element at the end