When array C is used as the form parameter, this parameter degrades to a pointer.

When an array is used as a function parameter, this parameter degrades to a pointer and cannot be used to directly obtain the array size.

The array is passed to a function. The array type is automatically converted to the pointer type, so the actual address is passed.
Void func (INT array [10])
Void func (INT array [])
Void func (int * array)
Therefore, the above three function declarations are completely equivalent.

The actual situation is that the array is used as a parameter and cannot be passed by value at all. This is determined by the implementation mechanism of C/C ++ functions.

The calculation of the array size is usually as follows:

Int Len = sizeof (ARR)/sizeof (type)

Obtain the length of the Array Based on the relationship between the total length and the length of a single element.

But as the form parameter, the length of sizeof (ARR) is 4, that is, the length of a pointer.

There are two ways to solve this problem:

Method 1.

When passing parameters, add a parameter directly as the length of the array.

Method 2. (incorrect)

Int * P = A [0];
Int ilen = 0;
While (P! = NULL)
{
Ilen ++;
* P ++;
}