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

type placeDetails = {
    house: string,
    mutable population: int
}

let placeDetails = {
  house: "Stark",
  population: 500000
};

type place = {
  name: string,
  placeDetails: placeDetails
};

let winterfell = {
  name: "Winterfell",
  placeDetails
};

winterfell.placeDetails.population = 100000;

Js.log(winterfell.placeDetails.population);

# Explanation
The `population` field has to be given the `mutable` keyword. Where will this change occurs? The type definition, of course. After this step, it's a simple matter of assigning a new value to the record's field. 

The `population` field can be accessed using the `.` operator.

This lesson explains the solution to the mutable nested fields exercise.

A Brief Introduction

Data Types

Identifiers

Data Structures

Conditional Expressions

Functions

Loops

Variants

Objects

Solution Review: Mutable Nested Fields