0, When you call DLL functions, you will need to pass these functions different parameters.
6, Parameters can be passed to these functions either by value or by reference.
12, Passing a parameter by value means that a copy of the data is actually passed to the DLL function.
18, The function is then free to change its value of the data because it has its own copy.
25, The variable that you pass by value to that function will not change.
30, Passing a parameter by reference means that only the address of the original variable is passed to the DLL.
38, Therefore, the DLL function can change the value of the original data.
44, Strings are passed to DLL functions by passing a pointer to that string by value.
50, The DLL function has passed its own copy of the pointer so the original value of the pointer can't be changed, but it can change the value of the string.
61, The pointer passed to the DLL gives the DLL the address to the memory of the string, so the DLL has full access to the string.
