When the C ++ array is used as a function parameter, the array size method is passed. The Function Array

When the C ++ array is used as a function parameter, the array size method is passed. The Function Array

If you don't talk much about it, let's demonstrate the error first:

Void fun (int arr [arr_num]) {

//...

}

 

Int main (){

//...

Int * arr = new int [10];

Fun (arr)

//...

Return 0;

}

Many users want to transfer the array size to the function to facilitate operations. Although the above method looks pleasing to the eye, it is wrong and arr_num does not play any role, that is to say, no matter how big the array you pass in is, no error is reported.

The correct method is as follows:

Method 1:

Pass the array size as another parameter

Void fun (int * arr, int arr_num ){

//...

}

Method 2:

Void fun (int (& arr) [arr_num]) {

//...

}

It has been tested that this method also has the following error:

1. When the passed parameter is not a pointer, this method is correct, that is:

Int arr [10] = {0 };

Fun (arr );

2. When the passed parameter is a pointer, this method returns an error, namely:

Int * arr = new int [10];

Fun (arr );

 

To sum up, the first method is relatively secure, and it is no big deal to add another parameter.