javascript - 为什么 `+0n` 会抛出错误，而 `-0n` 不会？

Question

以下代码在 javascript 中引发错误:

console.log(String(+0n))

但是这段代码运行成功:

console.log(String(-0n))

为什么 +0n抛出错误但 -0n才不是？

Answer 1

这样它doesn't break asm.js :

• Unary + followed by an expression is always either a Number, or results in throwing. For this reason, unfortunately, + on a BigIntneeds to throw, rather than being symmetrical with + on Number:Otherwise, previously "type-declared" asm.js code would now bepolymorphic.

如 Bergi评论中的亮点，这是三个选项中最差的一个:

+ BigInt -> BigInt:破坏 asm.js，以及任何其他做出“一元加号给出数字”的假设；

+ BigInt -> Number: 与 design decision 冲突禁止 Number 和 BigInt 之间的隐式转换；或

+ BigInt -> 错误。