Explore ReasonML's growing popularity and its strong-typed syntax for JavaScript. Learn about creating data objects, functions, and data structures through interactive quizzes and exercises.

ReasonML has been skyrocketing in popularity lately, and for good... reason. Very recently developed by Facebook, it provides users a strong-typed, clean, and efficient syntax for JavaScript, which makes it great for web development. 

This course will get you up to speed programming in Reason. You'll start by learning how to create simple data objects and build up to more powerful tools such as functions and data structures. Along the way, interactive quizzes and exercises will help you gain a stronger grasp of the language.

Anyone looking to put themselves on the cutting-edge of web development would be well served to have a look at this course.

Functional Programming with ReasonML

## The Restrictions of Closed Objects

The objects we've dealt with until now have been **closed objects**. In closed objects, we cannot define public functions unless they have been declared in the type definition. Any new members in the object's implementation would have to be *values* or *private methods*.

For example, take a look at the `circle` type below:

# The Restrictions of Closed Objects

The objects we've dealt with until now have been **closed objects**. In closed objects, we cannot define public functions unless they have been declared in the type definition. Any new members in the object's implementation would have to be *values* or *private methods*.

For example, take a look at the `circle` type below:

In this lesson, we'll learn about the functionality of open objects in Reason.

A Brief Introduction

Data Types

Identifiers

Data Structures

Conditional Expressions

Functions

Loops

Variants

Objects

Open Objects

The Restrictions of Closed Objects