es6数值解构Number.prototype.toString is not generic
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script>
({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
</script>
</body>
</html>
为什么b不能作为函数调用？
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1回答
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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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JavaScript