数组和长度C ++ [英] Arrays and length in C++

问题描述

我试图得到尽可能一些函数的参数传递的数组的长度。
在code是这样的：

I'm trying to get the length of an array passed as a parameter on some function. The code is look like this :

double getAverage(int numbers[])
{
    int length = sizeof(numbers)/sizeof(numbers[0]);
    // here the result of the length is 1.
    int sum = 0;
    for (int i = 0 ; i < length ; i++)
    {
        sum += numbers[i];
    }
    return (double)sum / length;
}

int main()
{
    int numbers[8] = {1,2,3,4,5,6,7,8};
    //if I call here sizeof(numbers)/sizeof(numbers[0] the result will be 8 as it   
    //should be.
    cout << getAverage(numbers) << endl;
    return 0;
}

我的问题是如何获得，通过引用作为函数的参数传递（虽然我知道每个数组通过引用传递）数组的长度？
我知道有很多关于寻找数组长度在C / C ++，但没有他们中的一个给我，我要找的答案的问题。
先谢谢了。

My question is how to get the array length which is passed as argument of a function by reference(although I know that every array is passed by reference)? I know that there is a lot of questions about finding the array length in C/C++ but no one of them give me the answer which I'm looking for. Thanks in advance.

推荐答案

如果你必须使用一个数组，你可以模板化的功能：

If you must use an array, you could 'templatize' your function:

template <size_t length> double getAverage(int (&numbers)[length]) {
    int sum = 0;
    for (int i = 0 ; i < length ; i++)
    {
        sum += numbers[i];
    }
    return (double)sum / length;
} 

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