es6数值解构Number.prototype.toString is not generic

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<title>Document</title>

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({toString:b} = 123);

console.log(b === Number.prototype.toString); // true

console.log(Number.prototype.toString()); // 0

console.log(b()); // Number.prototype.toString is not generic

let num = 456;

console.log(num.b()); // num.b is not a function

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为什么b不能作为函数调用？

茅侃侃

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1回答

守着一只汪

Number.prototype.toString 标准The toString function is not generic; it throws a TypeError exception if its this value is not a Number or a Number object. Therefore, it cannot be transferred to other kinds of objects for use as a method.翻译一下后面的：如果他的this值不是数字类型或者Number对象，将会抛出一TypeError直接调用this是window你可以这么用：b.call(1) b.call(Number('test'))

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