Quiz: Type Constructors (Answer)

  • Article

Lots of good comments on my little quiz, seems it was too easy, everyone got it right!

The first sample (in C# or VB) will print “17”. To see why, check out the ILDASM for the .cctor (which, BTW, is identical in VB and C#):

  IL_0000: ldc.i4.s 42

  IL_0002: stsfld int32 StaticConstructor.Foo::Value

  IL_0007: ldc.i4.s 17

  IL_0009: stsfld int32 StaticConstructor.Foo::Value

  IL_000e: ret

As you can see, the compilers emits the code for the inline static field initializer first (in this case the set to the value 42), then the user code for the .cctor (in this case the set to the value 17). So that means the type constructor will always take precedence.

As far as which “fix” is better. Setting the static field in line is better from every angle. It is less lines of code, easier to read and get right and, most importantly it is the best performing code with the most likelihood of getting even better in future versions of the CLR. Check this out for more information: Perf penalty Static Constructor