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JavaScript 内部字符串编码使用 UTF-16 https://www.ecma-international.org/ecma-262/9.0/index.html#sec-ecmascript-language-types-string-type
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| // 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 | |
| "👨👩👧👦".length === 11; | |
| "👨👩👧👦" === "\u{1F468}\u200D\u{1F469}\u200D\u{1F467}\u200D\u{1F466}"; | |
| "👨" === "\u{1F468}"; | |
| "👩" === "\u{1F469}"; | |
| "👧" === "\u{1F467}"; | |
| "👦" === "\u{1F466}"; | |
| [..."👨👩👧👦"]; // [ "👨", "", "👩", "", "👧", "", "👦" ] | |
| // 在 Unicode 支持不完善的系统上按退格键，能看到这些家庭成员一个接一个的消失。 | |
| // 一家人就是要齐齐整整 |
Webkit默认JS引擎JavaScriptCore里String的iterator实现，和Safari的执行结果一致。
Chrome下执行结果：
估计是length是11，不足的位数默认填充了undefined
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