If C# is not interpreted, then why is a VM needed?

Question

I have read a lot of controversy about C#, where some say it\'s interpreted, some say it\'s not. I do know it\'s compiled into the MSIL and then JITed when run, depending on

Answer 1

You are probably refering to CLR (an implementation of the specification CLI).

The CLI defines a specific type system, semantics of all the operations on these types, a memory model, and run-time metadata.

In order to provide all of the above, some instrumentation of the generated code must happen. One simple example is to ensure that larger-than-32-bit numerals are supported and that floating-point operations behave as per specification on every architecture.

In addition, to ensure correct behaviour of memory allocation, correct management of metadata, static initialisation, generic type instantiation and similar some additional processes must be present during the execution of your CLR code. This is all taken care of by the VM and is not readily provided by the CPU.

A quote from Wikipedia, for example:

The CLR provides additional services including memory management, type safety and exception handling.