迷渡 justjavac

在 npm 5.1 或者更低版本中，不存在 npx 命令。因此，你必须全局安装 create-next-app：

npm install -g create-next-app

然后再运行：

create-next-app

%GetOptimizationStatus return a set of bitwise flags instead of a single value, to access the value, you need to take the binary representation of the returned value. Now, for example, if 65 is returned, the binary representation is the following:

(65).toString(2).padStart(12, '0');
// 000001000001

Each binary digit acts as a boolean with the following meaning:

PDF完整版：https://github.com/huangjunsen/GooFlow/files/2078684/_.Issue.12.sdlddr_Gooflow.pdf

	// 需要通过 node --allow-natives-syntax 参数运行
	const { GCSignal, consumeSignals, trackGarbageCollection } = require("gc-signals");

	function fn() {
	// 创建两个局部变量
	const a1 = new GCSignal(1);
	const a2 = new GCSignal(2);
	global.tmp = a2; // 将 a2 变量赋值给全局变量
	const o = {};
	trackGarbageCollection(o, 3); // 跟踪局部变量 o 的 GC 状态，标识为 3

	// JavaScript 字符串编码使用 UTF-16
	"💩".length === 2;
	"💩" === "\u{1F4A9}"; // es6
	"💩" === "\uD83D\uDCA9"; // es5

	// 同一个编码可能使用不同的码位
	"ò" === "ò"; // ❎
	"ò" === "\xF2"; // ✅
	"ò" === "o\u0300"; // ✅
	"o\u0300".normalize("NFC") === "\xF2"; // ✅ es6 提供了 normalize 函数

	function wtf() {
	( [ {} ] )
	[ ( {} ) ]
	{ ( [] ) }
	}

	let reslt, x;

	reslt = [...null]; // TypeError: null is not iterable
	reslt = [...undefined]; // TypeError: undefined is not iterable

	reslt = {...null}; // {}
	reslt = {...undefined}; // {}

	if (x in null) {}
	// TypeError: Cannot use 'in' operator to search for 'undefined' in null

	function test() {
	const a = new Int32Array(10);
	for (let i = 0; i < 1e6; i++) {
	a.set([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
	}
	return a;
	}

	console.time('test');
	test();

	// https://github.com/chaosbot/Chaos/blob/master/server/static/js/chaos.js
	var canvas = document.createElement("canvas");
	document.getElementsByClassName("content")[0].appendChild(canvas);
	var ctx = canvas.getContext("2d");

	canvas.width = 400;
	canvas.height = 200;

	ctx.fillStyle = "#000000";
	ctx.fillRect(0, 0, canvas.width, canvas.height);