在不使用sizeof的情况下查找数组的大小 [英] Find size of array without using sizeof

问题描述

我正在寻找一种无需使用sizeof即可在C中查找数组大小的方法，并且发现了以下代码:

I was searching for a way to find the size of an array in C without using sizeof and I found the following code:

int main ()
{
    int arr[100];
    printf ("%d\n", (&arr)[1] - arr);
    return 0;
}

任何人都可以向我解释一下它是如何工作的吗?

Can anyone please explain to me how is it working?

推荐答案

&arr是指向100个int s数组的指针.

&arr is a pointer to an array of 100 ints.

[1]的意思是添加所指向对象的大小"，它是100个int s的数组.

The [1] means "add the size of the thing that is pointed to", which is an array of 100 ints.

所以(&arr)[1]和arr之间的差是100 int s.

So the difference between (&arr)[1] and arr is 100 ints.

(请注意，此技巧仅在sizeof仍然可以使用的地方有效.)

(Note that this trick will only work in places where sizeof would have worked anyway.)

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