Sprint Challenge: JavaScript Fundamentals

This challenge allows you to practice the concepts and techniques learned over the past week and apply them in a survey of problems. This Sprint explored JavaScript Fundamentals. During this Sprint, you studied variables, functions, object literals, arrays, this keyword, prototypes, and class syntax. In your challenge this week, you will demonstrate proficiency by completing a survey of JavaScript problems.

Read these instructions carefully. Understand exactly what is expected before starting this Sprint Challenge.

This is an individual assessment. All work must be your own. Your challenge score is a measure of your ability to work independently using the material covered through this sprint. You need to demonstrate proficiency in the concepts and objectives introduced and practiced in preceding days.

You are not allowed to collaborate during the Sprint Challenge. However, you are encouraged to follow the twenty-minute rule and seek support from your PM and Instructor in your cohort help channel on Slack. Your work reflects your proficiency in JavaScript fundamentals.

You have three hours to complete this challenge. Plan your time accordingly.

Commit your code regularly and meaningfully. This helps both you (in case you ever need to return to old code for any number of reasons) and your project manager.

You will notice there are several JavaScript files being brought into the index.html file. Each of those files contain JavaScript problems you need to solve. If you get stuck on something, skip over it and come back to it later.

In meeting the minimum viable product (MVP) specifications listed below, you should have a console full of correct responses to the problems given.

Demonstrate your understanding of this week's concepts by answering the following free-form questions.

Edit this document to include your answers after each question. Make sure to leave a blank line above and below your answer so it is clear and easy to read by your project manager

1. Describe the biggest difference between .forEach & .map.

.forEach doesn’t actually return anything. It just calls the function for each array element and then it’s done. So whatever you return within that called function is simply discarded. .map will similarly call the function for each array element but instead of discarding its return value, it will capture it and build a new array of those return values. This means that you could use map wherever you are using forEach but you still shouldn’t do that so you don’t collect the return values without any purpose. It’s just more efficient to not collect them if you don’t need them.

2. What is the difference between a function and a method?

In javascript every function is an object. An object is a collection of key:value pairs. If a value is a primitive (integer, string, boolean), or another object, the value is considered a property. If a value is a function, it is called a 'method'.

3. What is closure?

A closure is a feature in JavaScript where an inner function has access to the outer (enclosing) function's variables — a scope chain. The closure has three scope chains: it has access to its own scope — variables defined between its curly brackets. it has access to the outer function's variables. While methods ARE functions, methods are defined inside objects, while functions can be created on the global scope.

4. Describe the four rules of the 'this' keyword.

The value of this differs depending on how a function is invoked Window/Global Object Binding: When in the global scope, the value of “this” will be the window/console Object; Implicit Binding: this points to the object on which the function is called (what’s to the left of the period when the function is called). Explicit Binding: We can explicitly tell the JavaScript engine to set this to point to a certain value using call, apply or bind. New Binding: Using the new keyword constructs a new object, and this points it.

5. Why do we need super() in an extended class?

The extends keyword, and super(); function make it so trivial to bind our classes together to achieve some simple object inheritance. The extends keyword will abstract away any of the Class.call syntax that we’re used to. super() is used to tell a parent’s constructor to be concerned with the child’s attributes vis versa and abstracts away the Object.create(this, Class) syntax.

Follow these steps to set up and work on your project:

• Create a forked copy of this project.
• Add PM as collaborator on Github.
• Clone your OWN version of Repo (Not Lambda's by mistake!).
• Create a new Branch on the clone: git checkout -b <firstName-lastName>.
• Create a pull request before you start working on the project requirements. You will continuously push your updates throughout the project.
• You are now ready to build this project with your preferred IDE
• Implement the project on your Branch, committing changes regularly.
• Push commits: git push origin <firstName-lastName>.

Follow these steps for completing your project:

• Submit a Pull-Request to merge Branch into master (student's Repo).
• Add your Project Manager as a Reviewer on the Pull-request
• PM then will count the HW as done by merging the branch back into master.

Your finished project must include all of the following requirements:

Pro tip for this challenge: If something seems like it isn't working locally, copy and paste your code up to codepen and take another look at the console.

Test your knowledge of objects and arrays.

• Use the objects-arrays.js link to get started. Read the instructions carefully!

This challenge takes a look at callbacks and closures as well as scope.

• Use the functions.js link to get started. Read the instructions carefully!

Create constructors, bind methods, and create cuboids in this prototypes challenge.

• Use the prototypes.js link to get started. Read the instructions carefully!

Once you have completed the prototypes challenge, it's time to convert all your hard work into classes.

• Use the classes.js link to get started. Read the instructions carefully!

In your solutions, it is essential that you follow best practices and produce clean and professional results. Schedule time to review, refine, and assess your work and perform basic professional polishing including spell-checking and grammar-checking on your work. It is better to submit a challenge that meets MVP than one that attempts too much and does not.

There are a few stretch problems found throughout the files, don't work on them until you are finished with MVP requirements!!