JavaScript the Better Parts, by Douglas Crockford. 2018

Summary of Douglas Crockford JavaScript Better Parts

Pre-JS2015

• stop using new (operator)
• stop using Object.create
• stop using this (binding)
• stop using null
• stop using “falsiness”. (do not use Double Equal Operator, use Triple Equal Operator, and make sure in if statement, the test always return true/false (boolean) )

• stop using for-loop 〔see for while do Loop〕
• stop using for-in Loop. Use forEach
• stop using while statement. Use tail recursion.

Crockford's JS2015 Bad Parts

• Never use Class. (misleading prototype object system with class object system.)

• Proxy (says its too complex.)
• Generator. (says its not necessary, complex, and confusing syntax.)
• Iterator
• Symbol
• Reflect (says its confusing and complex.)
• Arrow Function. (says the syntax is confusing, looks like relation. And the wart of returning a object must have return.)

Crockford's JS2015 Good Parts

• let Declaration
• const Declaration
• Destructuring Assignment
• WeakMap
• Spread Operator

Douglas Crockford JavaScript object system

• Traditional class object system (e.g. Java) is inflexible, no multi-inheritance (OOP diamond problem), hard to get the hierarchy correct, and impossible to change later.
• Crockford used to like JavaScript prototype object system. But not today. Never actually seen changing parent useful. Suffer from slow performance.

Crockford recommend a object system, written this way: