What is the differences between int* and IntPtr ?

Question

Just curious about the difference of those things in C# : int* and IntPtr ?

And also :

int varTest = 123;

IntPtr PT = (IntPtr)(&varTest);

int* PointerTo = &varTest;

long LongAdd = (long)PointerTo;

int IntAdd = (int)PointerTo;

MessageBox.Show(LongAdd.ToString());  //Same
MessageBox.Show(IntAdd.ToString());  //Same
MessageBox.Show(PT.ToString());  //Same

Answer 1

Hi Arsium-4135,
int* i means that the type of i is "pointer to int" and you read it as i is a pointer to an integer.
That is to say , the first part represents the variable type (pointer to int), and the second part represents the name (i).
The IntPtr type is designed to be an integer whose size is platform-specific. That is, an instance of this type is expected to be 32-bits on 32-bit hardware and operating systems, and 64-bits on 64-bit hardware and operating systems.
It is called IntPtr because to use it from unmanaged native code C/C++, you will have to use the analog type: intptr_t. C#'s IntPtr is fully mapped to C/C++'s intptr_t. It may be implemented as intptr_t. In C/C++, ensure that the size of intptr_t type is the same as the size of void* type.
And you need to put your code into unsafe{...}.
More details you can refer to the following links.
Just what is an IntPtr exactly?
IntPtr Struct
Best Regards,
Daniel Zhang

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