DEV Community

Charbel Sarkis
Charbel Sarkis

Posted on

Exploring javascript

Yet another free online book that I'm tho it is worth buying.

Object.freeze does exactly that except it is shallow

ToObject throws errors upon encountering null and undefined

0.1 + 0.2 !== 0.3 floating point numbers can't be represented accurately. Although numbers close to 0 can be stored more accurately

Accurate Math Functions. Math.expm1 Math.log1p
Used for asm.js Math.fround Math.imul

Bitwise operations Math.clz32(0b0000001)

You can represent bytes/hex/octal by adding 0b 0x 0o respectively to the beginning of a string

To avoid versioning -- that thing that happened with python -- javascript made itself backwards compatible. Which proved to be difficult since old code could break upon changing. So they added "strict mode" which gives you all the new errors and enhancements to the language. This is enabled by default in classes and in modern web frameworks, you can however enable it in a single function only by adding "use strict".

Add mixins to JavaScript

There is the capability of making factories or lazy generators in JavaScript

Iterators with Symbol.Iterator

You can extend an Error class in javascript.

There are maps in javascript

BigInt in javascript

Static method to Number. IsSafeInteger Number.MAX_SAFE_INTEGER Number.parseInt Number.parseFloat Number.isNAN Number.EPSILON Number.isInteger Number.isFinite

Implementing tag functions

JavaScript Symbols

why const prevents the weird closure bug

const creates one binding per iteration, var creates one binding per loop. That is why const solves the closure bug.
https://exploringjs.com/es6/ch_variables.html#sec_rationale-per-iteration-bindings

https://exploringjs.com/es6/ch_variables.html#sec_rationale-per-iteration-bindings

Cool websites about Javascript

javascript.info
v8.dev
Crossing realms with symbols

Top comments (1)

Collapse
 
charbelsako profile image
Charbel Sarkis

If anyone has anything quirky or useful about JavaScript, I am all ears. This will be my repo for knowledge about JavaScript in the future.

On a side note, apparently you can know make web components natively, since when did this happen?