[V3] Implement new Concept Exercise: Function Expression and ES6 Arrow Function

[shubhsk88]

This issue describes how to declare the function expression and declaration with the ES6 Arrow function.

This issue describes how to implement the function concept exercise for the Javascript track.

Getting started

Please please please read the docs before starting. Posting PRs without reading these docs will be a lot more frustrating for you during the review cycle and exhaust Exercism's maintainers' time. So, before diving into the implementation, please read up on the following documents:

• The features of v3.
• Rationale for v3.
• What are concept exercise and how they are structured?

Please also watch the following video:

• The Anatomy of a Concept Exercise.

Goal

This exercise aims to tell the student about the declaration of function, arrow function.

For example:

• function hello ( ) { }
• let hello = function ( ) { }
• const hello = ( ) => { }

Learning objectives

• The student able to figure out the difference between function declaration and function expression.
• The student able to know how the arrow function can be implemented and where to use it.
• Explaining the definition of high order function

Out of scope

• Closures
• Use of arrow function in the context of this keyword;
• Callbacks

Concepts

• function declartions

Prerequisites

• functions-intro
• variables

After

• Understanding of execution context of the function
• Higher-order function
• When to use function declarations or function expressions

Help

If you have any questions while implementing the exercise, please post the questions as comments on this issue.

[SleeplessByte]

Cool!

I don't think higher order functions are in scope.

I think it will be hard to test for use of one of the variants, BUT we can write an analyzer to do that instead.

Interesting would be:

• name of the function
• binding of this (as well as other context such as arguments)

Since this is a hard concept to teach clearly, I would recommend writing up ideas in this issue first before commuting a lot of time to it. 🤗

[junedev]

I am closing this issue because we decided to cut the concepts/concept exercises differently. See #951 (comment) for details. Arrow functions will be combined with callbacks in one exercise and function expression are covered in the functions concept/concept exercise.