Index, assignment and increment in one statement behaves differently in C++ and C#. Why?

Question

Why is this example of code behaving differently in c++ and C#.

[C++ Example]

int arr[2];
int index = 0;
arr[index]         


        

Answer 1

index in C# is a value type, which means you return a new instance of the value when you perform operations on it.

If you imagine it as a procedure instead of an operator, the procedure would look like this:

public int Increment(int value)
{
   int returnValue=value+1;
   return returnValue;
}

C++, however, works on the reference of the object, so the procedure would look like:

int Increment(int &value)
{
   value=value+1;
   return value;
}

Note: if you had been applying the operator on an object (say overloaded the ++ operator) then C# would behave like C++, since object types are passed as references.