1
Implement a simple Finite State Machine library in JavaScript
9m 30s
2
Array reduce vs chaining vs for loop
6m 13s
3
Reduce cognitive load for readers of your code by avoiding nesting of closures
3m 15s
4
Fix "React Error: Rendered fewer hooks than expected"
4m 17s
5
Get started with Web Workers
3m 18s
6
Organization of Authentication State in React Apps
5m 16s
7
Get started with Netlify Serverless Functions
3m 27s
8
Implement Inversion of Control
7m 11s
9
Implement useState with useReducer
5m 40s
10
Use JavaScript Modules in the browser
8m 30s
11
Fix the "not wrapped in act(...)" warning when testing the useImperativeHandle Hook
2m 1s
12
Fix the "not wrapped in act(...)" warning with Jest fake timers
2m 51s
13
Fix the "not wrapped in act(...)" warning when testing Custom Hooks
2m 2s
14
Fix the "not wrapped in act(...)" warning
6m 5s
15
Create App DevTools to enhance development productivity
9m 50s
16
Make Your Test Fail
4m 16s
17
Use a status enum instead of booleans
7m 43s
18
When to useState instead of useReducer
5m 2s
19
When to useReducer instead of useState
10m 6s

Implement Inversion of Control

JavaScript

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Inversion of Control is a simple principle that can drastically improve your reusable code. In this lesson we'll go over the concept and you'll get an idea of how you can apply it for your own abstractions.

This is based on my blog post: Inversion of Control

Course

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Daniel Deverell

~ 5 years ago

Thanks for this. I will definitely be using inversion more in the future. Note to others: at the end of the video you probably want legCount set in the filterByLegCount function:

function filterByLegCount(array, legCount) {
  return filter(array, animal => animal.legs === legCount);
}

Chandrasekar Arunachalam

~ 5 years ago

Hello Kent,

Correct me if I'm wrong. To check undefined and null like this (element !== null && element !== undefined). Hope the following will work (element != null) this checks both undefined and null.