迷渡 justjavac

## wtf.js
function wtf() {
  ( [ {} ] )
  [ ( {} ) ]
  { ( [] ) }
}

## unicode.js
// 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

## GetOptimizationStatus.md

      
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              7 stars
            
          
                justjavac
                / GetOptimizationStatus.md
            
            
              Last active
              March 31, 2024 06:30
            
              
                V8 %GetOptimizationStatus
              
          
    %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:

  
## instructions.md

      
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                justjavac
                / instructions.md
            
            
              Last active
              August 23, 2019 01:10
                — forked from Timer/instructions.md
            
              
                使用 npm <= 5.2 创建新项目
              
          
    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

  
## gc-track.js
// 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
	// 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