06 - 02 - Iteration in JavaScript

[aksnell]

Objectives

After completing this assignment, you should be able to:

• Demonstrate understanding of iteration/enumeration

Instructions

1. Fork this repository to your own account.
2. Change into your projects directory:
3. Clone your repository: hub clone js-iteration
4. Change into your project's directory: cd js-iteration
5. Install the dependencies: yarn install (or just yarn for short)
6. Open in your editor]
7. Start the test runner: yarn test
8. Open src/functions.test.js and work on functions until tests pass.
9. Commit and push your work to GitHub.
10. Turn in the URL to your GitHub repo.

Explorer Mode

• All tests passing

Epic Mode

• Using the forEach looping method and no other looping or enumeration helper, write your own version of the following methods, except name yours _map, _filter, etc.
  • map
  • filter
  • reduce
  • every
  • some
• Write some example usage of your new methods to demonstrate that they work

Additional Resources

Reference the documentation on DevDocs to find what kind of helpful functions might already be in JavaScript.

• String Functions on DevDocs.
• Array Functions on DevDocs.

[aksnell]

https://github.com/aksnell/js-iteration

All tests passing, etc.

I can do the epic mode challenge, but I spent way to long trying to see if I could extend the actual array prototype (I understand why this is a terrible idea to never do for real) and I could not make Object.defineProperty and by then I had to move on to other work.

https://repl.it/@theoriginalaks/IntelligentGeneralDeletion#index.js

I have literally no idea whats wrong, it seems to my tired eyes, identical to every example I can find.

[gstark]

Use string interpolation here: return array.map((str, index) => str + " is at index " + index.toString())

It is something in the repl.it environment.

On my computer:

~ » node
Welcome to Node.js v14.4.0.
Type ".help" for more information.
> Array.prototype.myMap = () => console.log('hello')
[Function (anonymous)]
> [].myMap()
hello

On repl.it

 Array.prototype.myMap = () => console.log('hello')
[Function]
 [].myMap()
TypeError: [].myMap is not a function
    at repl:1:4
    at Script.runInContext (vm.js:131:20)
    at REPLServer.defaultEval (repl.js:433:29)
    at bound (domain.js:426:14)
    at REPLServer.runBound [as eval] (domain.js:439:12)
    at REPLServer.onLine (repl.js:759:10)
    at REPLServer.emit (events.js:310:20)
    at REPLServer.EventEmitter.emit (domain.js:482:12)
    at REPLServer.Interface._onLine (readline.js:322:10)

Perhaps it is the way they are running the code, or a "security" feature.

[aksnell]

Your homework 06 - 02 - Iteration in JavaScript was marked: Meets Expectations

“Well done!”