为什么 Number.isNaN() 为字符串返回 false? [英] Why does Number.isNaN() return false for Strings?

问题描述

根据我的理解 NaN 代表 Not A Number.字符串 不一定是数字，因此我希望下面的代码为字符串返回true.然而，事实并非如此.

As per my understanding NaN stands for Not A Number. Strings are not definitely Numbers and hence I expect the below code to return true for Strings. However, it's not the case.

console.log(Number.isNaN("Stack Overflow"));

有人可以澄清一下吗?

推荐答案

Number.isNaN 和 isNaN

https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/isNaN

isNaN() 函数确定一个值是否为 NaN.

The isNaN() function determines whether a value is NaN or not.

https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Number/isNaN

Number.isNaN() 方法判断传入的值是否为 NaN，类型是否为 Number.它是原始全局 isNaN() 的更强大版本.

The Number.isNaN() method determines whether the passed value is NaN and its type is Number. It is a more robust version of the original, global isNaN().

您返回 false 的原因是堆栈溢出"不是数字，而是字符串.

The reason you are returning false is that "Stack Overflow" is not a number it is a string.

console.log('Number.isNaN("Stack Overflow"): '+Number.isNaN("Stack Overflow"));
console.log('isNaN("Stack Overflow"): '+isNaN("Stack Overflow"));

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