In this book, you will find how to use JavaScript as a functional programming language.

It turns out that JavaScript has everything it needs to be used as a functional language. We just have to remove features from the language starting with the 'this' keyword.

Functions are values. Functions can operate on other functions. Inner functions can access variables from the outer functions even after the outer functions have been executed.

Functional programming makes code easier to read, understand, test, and debug.

Here are some of the things you will learn:

• How to disable 'this' and enable immutable data objects using a linter
• How to work with immutable objects and collections
• How to do data transformations using core operations like filter, map, sort, or reduce
• How to use statements like if and switch in a functional way
• How to create pipelines and use currying to pass additional data
• Understand functors and monads
• How to work with promises and observables
• Understand the Elm Architecture