C / C ++ in the array as a function of the parameter pointers back into

Recently wrote a function, the array as its parameters, the length of the array used in this function, the normal length of seeking the way, should not go wrong; but after running findings is not what I want. Then write a test program to verify my guess.

#include <iostream>

using namespace std;

void Sort(int nSortArray[6])
{
    int nLen = sizeof(nSortArray) / sizeof(nSortArray[0]);
    int nTmp = 0;
    for (int i = 0; i < nLen; i++)
    {
        for (int j = i+ 1; j < nLen; j++)
        {
            if (nSortArray[i] > nSortArray[j])
            {
                nTmp = nSortArray[i];
                nSortArray[i] = nSortArray[j];
                nSortArray[j] = nTmp;
            }
        }
    }
}

int main()
{
    int nArray[6] = { 0, 8, 3, 2, 10, 9 };
    cout << "排序前......" << endl;
    for (int i = 0; i < sizeof(nArray) / sizeof(nArray[0]); i++)
    {
        cout << nArray[i] << "," ;
    }
    cout << endl;
    Sort(nArray);
    cout << "排序后......" << endl;
    for (int i = 0; i < sizeof(nArray) / sizeof(nArray[0]); i++)
    {
        cout << nArray[i] << "," ;
    }

    system("pause");
    return 0;
}

The code is sorted into an array print found, and the results before and after no change, breakpoint debugging find its length only 1; as follows:

That length sizeof (nSortArray) length and sizeof (nSortArray [0]) are equivalent, while sizeof (nSortArray [0]) is the length of the first address of the array, i.e., it corresponds to a pointer to the first array position value; then the results come out naturally, nSortArray as the parameter, just as the use of a pointer that points to the first location of the array. Therefore, the correct wording should be as follows:

#include <iostream>

using namespace std;

void Sort(int nSortArray[], int nLen)
{
    int nTmp = 0;
    for (int i = 0; i < nLen; i++)
    {
        for (int j = i + 1; j < nLen; j++)
        {
            if (nSortArray[i] > nSortArray[j])
            {
                nTmp = nSortArray[i];
                nSortArray[i] = nSortArray[j];
                nSortArray[j] = nTmp;
            }
        }
    }
}

int main()
{
    int nArray[6] = { 0, 8, 3, 2, 10, 9 };
    cout << "排序前......" << endl;
    for (int i = 0; i < sizeof(nArray) / sizeof(nArray[0]); i++)
    {
        cout << nArray[i] << "," ;
    }
    cout << endl;
    Sort(nArray, sizeof(nArray)/sizeof(nArray[0]));
    cout << "排序后......" << endl;
    for (int i = 0; i < sizeof(nArray) / sizeof(nArray[0]); i++)
    {
        cout << nArray[i] << "," ;
    }

    system("pause");
    return 0;
}

The code can be seen from the above, in addition to the array as a parameter a pointer degradation, all other cases the normal length of the array is obtained