In this course, you will learn to create your own interactive data visualizations for the web with D3.js, a very popular JavaScript library. 

Starting with the fundamentals, you'll learn about SVG, selections, classes, and styles, as well as displaying data. This will give you the base to start working with more advanced concepts. 

Once you’ve got the basics out of the way, you will start practicing drawing various scatter plots, where you’ll learn all the best practices for creating stunning visualizations.

Lastly, you will dive into scales and one of the more fun parts: adding animation and interactivity.

By the time you finish this course, you will have a powerful new library to add to your resume, and you’ll be able to transform data into meaningful insights.

Master D3.js for Data Visualization

The `data()` method we used previously returned a selection object. However, the selection object is slightly different from other selection objects we have worked with thus far. There are two new properties called `_enter` and `_exit`. We will be discussing what the enter selection is in this lesson.

## What is the enter selection?

Joining data can become complex when the ratio between data and elements is not 1-to-1. If we have more elements than we have data, we should remove excess elements. If there are fewer elements than we have data, we should add more elements.

In the developer tools, the selection object returned was different from the previous selection objects.

The `data()` method we used previously returned a selection object. However, the selection object is slightly different from other selection objects we have worked with thus far. There are two new properties called `_enter` and `_exit`. We will be discussing what the enter selection is in this lesson.

# What is the enter selection?

Joining data can become complex when the ratio between data and elements is not 1-to-1. If we have more elements than we have data, we should remove excess elements. If there are fewer elements than we have data, we should add more elements.

In the developer tools, the selection object returned was different from the previous selection objects.

D3 introduces two new selections called enter and exit. Let's discuss what the enter selection is

Overview

SVG Basics

D3 Fundamentals

Drawing a Scatter Plot

Scales

Animations & Interactivity

Even More Charts!

Conclusion

The Enter Selection

What is the enter selection?