Javascript Arrays Made Simple: Map and Flat (Part 4)

Map is probably the most important single array method you will learn, particularly if you are a React developer. Let's dig into the powerful map method, and its associated methods to see just what we can do with them.

👉 What's my theme? Night Wolf [black]
👉 What's that font? Operator Mono

00:00 Introduction
00:22 Map of scalars
01:45 Chaining filter and map
03:07 Mapping over objects
05:25 Nested object references
06:39 Cheap cloning
08:52 Flat
10:07 flatMap
11:09 Concat
12:09 Review
12:52 Outroduction

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#javascript #arrays

[wahidy]

I am waiting for the time When this Chanel hits millions of subs and I can proudly say I am from the good old days. Thanks Jack!!

[BezzantSam]

I just got a message from a lady in my school saying the way you explain things is better than all of the huge channels out there.

[Raubritterr]

Jack, I'm learning so much from you, it's unbelievable!
I'm on my journey to switching careers and becoming a (frontend) developer, and your content is just pure gold.
Thank you for all your efforts, and may you and your family and friends be healthy and happy!

[markgnetsg]

Great stuff Jack, your videos are pure gold, thanks for donating your time and helping others to get ahead.

[BezzantSam]

This is chock full of great info. I pulled up vs code and wrote this one out with the video. The minimalistic power of chaining has me wanting to barf thinking about for loops.

[sukeshkumard]

Hi Jack,
These are the best videos on Array methods, the kind of explanation and examples you gave are too good. Thank you Jack for making these videos.

[saeed]

Thank you so much Jack!🙏🏻 loving this series on arrays, totally Awesome! Wishing you much success!

[soltiscd]

This is really good information. I like the way you present the material. Great job all around.

[ram-bkmu]

This is just so satisfying to watch! thank you Sir!

[ThEldeRS]

I love these videos Jack! Would you mind sharing your sources about performance of the different methods? Happy thanksgiving!

[mariokrstevski]

I didn't know you can pass Infinity into flat, I had to implement my own recursive magic. NICE

[micoberss]

Thank you Jack for great lessons. I just checked stackoverflow on performance differences between .concat() and spread syntax. Array.prototype.concat() is slightly faster than destructuring arrays.

[victorlongon]

Probably using spred on complex objects with more than one level and mutating nice video, Jack. I think you make it very clear for people start working with array! This stuff with cloning with spread for complex objects is probably one of the most confusing things and source of bugs when you first start working with objects like that. 😅. One of the few utils i reach for nowadays.

[darkaos]

Thank you very mucho Jack. Greetings from México.

[mortezatourani]

Like always enjoyed and learned something new

[airixxxx]

Hello, love your videos, I wonder how do you display variable values on the side in real time, is that an vscode extension?

[Arunnn]

I've looked at quite a few npm code bases and if they ever need to copy an object, I've always seen them use JSON parse -> stringify. It may be slower but it's much easier

[campeone]

hi why do you need to wrap the curly braces in parentheses when you want to create an object in the minute 01:24?

[mohammad__re__]

I wish I could give more likes to your videos...
you are awesome 😉😎

[adamtak]

No matter how much I learn the syntax and what arrays/objects, etc are I can't seem to understand how they are used in the real world to solve real problems. Yeah I can solve the simple leet code questions but I if you were to ask me to solve something and write a bunch of functions to solve that problem, I'd just end up being lost as to what to do. Any advice?