Does the order of extern and static matter?

Question

Comparing two files (old and new), I see:

private extern static void SipShowIM(uint dwFlag);

...in the old file, and:

private static extern void SipShowIM(uint dwFlag);

...in the new file.

Why they got changed I don't know; does it matter which comes first, the extern or the static?

UPDATE

Resharper must have done this, because I know I didn't do this (directly) but here's another difference between old:

public volatile static bool ProcessCommands = true;

...and new:

public static volatile bool ProcessCommands = true;

Answer 1

No, the order of those keywords does not matter.

Answer 2

Well, I don't believe there is a difference between this two usage. I just consider the code of MSDN page, I tried the both way (extern static and static extern) and the both code generate the same IL code.

.method public hidebysig static int32  Main(string[] args) cil managed
{
  .entrypoint
  // Code size       41 (0x29)
  .maxstack  4
  .locals init ([0] string myString,
           [1] int32 CS$1$0000)
  IL_0000:  nop
  IL_0001:  ldstr      "Enter your message: "
  IL_0006:  call       void [mscorlib]System.Console::Write(string)
  IL_000b:  nop
  IL_000c:  call       string [mscorlib]System.Console::ReadLine()
  IL_0011:  stloc.0
  IL_0012:  ldc.i4.0
  IL_0013:  call       native int [mscorlib]System.IntPtr::op_Explicit(int32)
  IL_0018:  ldloc.0
  IL_0019:  ldstr      "My Message Box"
  IL_001e:  ldc.i4.0
  IL_001f:  call       int32 ProgramConsole.Program::MessageBox(native int,
                                                                string,
                                                                string,
                                                                int32)
  IL_0024:  stloc.1
  IL_0025:  br.s       IL_0027
  IL_0027:  ldloc.1
  IL_0028:  ret
} // end of method Program::Main

So, my money is for NO.

Answer 3

No, according to the C# specification, all method modifier orderings are equivalent. Version 4.0, section B.2.7, page 493:

method-modifiers:
      method-modifier
      method-modifiers method-modifier

method-modifier:
      new
      public
      protected
      internal
      private
      static
      virtual
      sealed
      override
      abstract
      extern

This clearly isn't a static constructor, but on page 497 (still section B.2.7), both orders are explicitly called out:

static-constructor-modifiers:
      extern_opt static
      static extern_opt

Answer 4

The order of method modifiers doesn't matter. It is however usually written as static extern.

Tools like StyleCop complain about that: SA1206: The 'static' keyword must come before the 'other' keyword in the element declaration. It is just a matter of coding style.