Well, okay, the title is a bit exaggerated. It should probably read "The RECOMMENDED JavaScript You Should Know When You Code React & Redux." But then again, it will be less click-baity, less controversial, and most certainly generate less sales That aside, if you pick this book, chances are your team is migrating to React/ Redux or your architecture team has decided that the React/ Redux is the "strategic" UI framework to adopt for the enterprise.You searched on Google for "react redux tutorial" and you found lots of JavaScript syntaxes alien (probably because you're from a Java/ C# background and the last time you coded JavaScript was a tiny validation script using JQuery in 2008). But that's no biggie You embrace the virtue of continuous learning. You brag about: "I'm a polyglot developer yo ." And then, you decided to get several books on JavaScript: probably Eloquent JavaScript, JavaScript Allonge or even Understanding ES6. But Argh they are all too verbose. Most of all, you are NOT a programming noob You know what variables and conditional constructs are. You simply don't have time to waste on these basics. Well, I've been there too buddy. And that's why I wrote this pocket book (aka cheatsheet) to prep people like you transition quickly from basic JavaScript & intermediate programming knowledge to being able to productively follow through React/ Redux tutorials on the web.Godspeed