为什么math.max（）返回带有整数数组的NaN？ [英] why math.max() returning NaN with array of integers?

问题描述

我想从一个简单的数组获得最高数字：

data = [4, 2, 6, 1, 3, 7, 5, 3];

alert(Math.max(data));

我已经读过如果数组中的其中一个值无法转换为数字，它将返回 NaN ，但在我的情况下，我已经用 typeof 进行了双重检查，以确保它们都是数字那么我的问题是什么呢？

I have read that if even one of the values in the array can't be converted to number, it will return NaN, but in my case, I have double-checked with typeof to make sure they are all numbers, so what can be my problem?

推荐答案

您的代码不起作用的原因是因为 Math.max 期望每个参数都是有效数字。这在文档中指出如下：

The reason why your code doesn't work is because Math.max is expecting each parameter to be a valid number. This is indicated in the documentation as follows:

如果至少有一个参数无法转换为数字，则结果为NaN。

If at least one of arguments cannot be converted to a number, the result is NaN.

在你的实例中，你只提供1个参数，而1个值是一个数组而不是一个数字（它没有检查数组中的内容，它只是停在知道它不是一个有效的数字。）

In your instance you are only providing 1 argument, and that 1 value is an array not a number (it doesn't go as far as checking what is in an array, it just stops at knowing it isn't a valid number).

一种可能的解决方案是通过传递一个参数数组来显式调用该函数。像这样：

One possible solution is to explicitly call the function by passing an array of arguments. Like so:

Math.max.apply(Math, data);

这实际上与您手动指定不带数组的每个参数相同：

What this effectively does is the same as if you manually specified each argument without an array:

Math.max(4, 2, 6, 1, 3, 7, 5, 3);

正如您所看到的，每个参数现在都是一个有效数字，因此它将按预期工作。

And as you can see, each argument is now a valid number, so it will work as expected.

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