Why (and how) does the order of an Enum influence the ToString value?

Question

I have problems with the "order" of the values of an enum. It\'s a little difficult to explain, that\'s why I wrote up some code:

class Program
{
    pu         


        

Answer 1

The first thing to observe, if you decompile the IL, is that the calls to WriteLine all look remarkably similar:

    L_000c: ldc.i4.1 
    L_000d: box ConsoleApplication2.Program/EnumA
    L_0012: call void [mscorlib]System.Console::WriteLine(object)
    L_0017: nop 
    L_0018: ldc.i4.1 
    L_0019: box ConsoleApplication2.Program/EnumA
    L_001e: call void [mscorlib]System.Console::WriteLine(object)
    L_0023: nop 
    L_0024: ldc.i4.1 
    L_0025: box ConsoleApplication2.Program/EnumA
    L_002a: call void [mscorlib]System.Console::WriteLine(object)
    L_002f: nop 
    L_0030: ldc.i4.4 
    L_0031: box ConsoleApplication2.Program/EnumA
    L_0036: call void [mscorlib]System.Console::WriteLine(object)
    L_003b: nop 
    L_003c: call void [mscorlib]System.Console::WriteLine()
    L_0041: nop 

That is, the loading of these enum values is loading the value "1" three times, and then calling WriteLine. So we should not be surprised that the 1st 3 calls all result in the same value.

I've tried a few experiments, but can't point to any particular (undocumented) behaviour you can rely on to predict which value will be printed.