问题描述
String.fromCodePoint(...[127482,127480]) 给我一面美国国旗 (??)。
如何将标志转回 [127482,127480]？
解决方法
您正在寻找 codePointAt，也许使用传播（等）转换回数组，然后映射每个。
console.log(theString.codePointAt(0)); // 127482
console.log(theString.codePointAt(2)); // 127480
// Note −−−−−−−−−−−−−−−−−−−−−−−−−−^
// It's 2 because the first code point in the string occupies two code *units*
或
const array = [...theString].map(s => s.codePointAt(0));
console.log(array); // [127482,127480]
或通过 Sebastian Simon pointed out 及其映射回调跳过作为 Array.from 的临时步骤：
const array = Array.from(theString,s => s.codePointAt(0));
console.log(array); // [127482,127480]
示例：
const theString = String.fromCodePoint(...[127482,127480]);
console.log(theString.codePointAt(0)); // 127482
console.log(theString.codePointAt(2)); // 127480
const array = [...theString].map(s => s.codePointAt(0));
console.log(array); // [127482,127480]
const array2 = Array.from(theString,s => s.codePointAt(0));
console.log(array2); // [127482,127480]Spread 和 Array.from 都使用字符串 iterator 工作，它通过代码点工作，而不是像大多数字符串方法那样工作的代码单元。