Question

I long for those sweet optional arguments from the days when I programmed in C++ more. I know they don’t exist in C#, but my question is Why.

I think method overloading is a poor substitute which makes things messy very quickly.

void foo(int x,int y,int z=0){
  //do stuff...
}

//is so much more clean than

void foo(int x,int y){
  foo(x,y,0);
}
void foo(int x,int y,int z){
 //do stuff
}

I just do not understand what the reasoning is. The C# compiler would obviously not have a problem supporting this just Microsoft elected not to support it.

Why, when C# was designed, did they not want to support optional arguments?

Answer 1

As Andrey says, C# 4 has optional parameters and named arguments. However, it’s worth pointing out that one of the concerns which made Anders reluctant to include them to start with – namely that the default value (which has to be a constant) gets baked into the calling code – is still present. In other words, it’s the same problem as publicly accessible const values from C# 1.