YiChu Go7hic

@kangax's ES6 quiz, explained

@kangax created a new interesting quiz, this time devoted to ES6 (aka ES2015). I found this quiz very interesting and quite hard (made myself 3 mistakes on first pass).

Here we go with the explanations:

Question 1:

(function(x, f = () =&gt; x) {

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Element

Box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent
elem.clientLeft, elem.clientTop, elem.clientWidth, elem.clientHeight
elem.getClientRects(), elem.getBoundingClientRect()

常用的 HTML 头部标签

详细介绍参见原文：yisibl/blog#1

<!DOCTYPE html> <!-- 使用 HTML5 doctype，不区分大小写 -->
<html lang="zh-cmn-Hans"> <!-- 更加标准的 lang 属性写法 http://zhi.hu/XyIa -->
<head>
    <meta charset='utf-8'> <!-- 声明文档使用的字符编码 -->
    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" /> <!-- 优先使用 IE 最新版本和 Chrome -->

	var http = require('http');

	/**
	* 读取远程文件
	*
	* @param {String} url
	* @param {Function} cb
	* - {Error} err
	* - {Buffer} buf
	*/

	// Sort Numbers
	function solution(nums){
	return (nums \|\| []).sort(function(a, b){
	return a - b
	});
	}

	// -------------------------------------------------------------------------------------------------------------------------

	// If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9.