Why is no warning given for this unused variable?

Question

When compiling the following program in VS2010, VS2008 or MonoDevelop on Windows, I get warning CS0219, \"The variable \'y\' is assigned but its value is never used\".

Answer 1

It could be that since x is a reference type, and is thus stored on the heap, that it would prevent garbage collection of that object until x goes out of scope.

For example:

void main(string[] args)
{
    object x = new object();
    while (true)
    {
        // Some threading stuff
        // x is never garbage collected
    }
}

In contrast to:

void main(string[] args)
{
    new object();
    while (true)
    {
        // Some threading stuff
        // The unreferenced object IS garbage collected
    }
}