Alternative to C# default parameters?

I want to use default parameters on this "lightswitch" function. However, the Unity compiler doesn't allow default parameters; so I get a compiler error.

(Note: code is simplified for this thread)

Code (CSharp):

1. // BAD CODE
2. void SwitchUp(float AnimationSpeed = 1.0f) {
3.         SwitchAnim ["MySwitchAnimation"].speed = AnimationSpeed;
4.         SwitchAnim.Play ("MySwitchAnimation");
5.     }

I've read that you can change to another compiler, but I want my code shareable. So now, my function looks like this:

Code (CSharp):

1. // global variable
2. public float AnimationSpeed;
3.  
4. void SwitchUp() {
5.         SwitchAnim ["MySwitchAnimation"].speed = AnimationSpeed;
6.         SwitchAnim.Play ("MySwitchAnimation");
7.     }

When I call this function passing a value of 3, I have to put:

Code (CSharp):

1.  
2. float PrevAnimationSpeed = AnimationSpeed;
3. AnimationSpeed = 3.0f;
4. SwitchUp();
5. AnimationSpeed = PrevAnimationSpeed;
6.  

Messy I know, and potentialy dangerous (if I ever get an error in SwitchUp())

Don't ask why, but I plan to call this function several times with different values for AnimationSpeed. That's a lot of extra lines of code!

Is there a better coding technique?

 

You can and I do use default parameters often.

Your supposedly bad code compiles just fine.

 

What compiler error? I use default parameters all the time. They work fine.

And if they didn't, yes, there would be a better work-around (method overloading). Do NOT use a global variable in place of a parameter, or you will suffer greatly.

 

MyLightSwitchScript.cs(26,26): Error CS0241: Default parameter specifiers are not permitted (CS0241) (Assembly-CSharp)

Just discovered I'm using .NET 3.5 framework which is the problem. The thing is, I don't want make it mandatory to change the compiler to 4.0 each time I compile this code on a different machine or share it online.

Maybe I have no choice?

 

...just thought of this, perhaps I could use function overloading instead...

 

Your only choices are .NET 2.0 or .NET 2.0 Subset. And default parameters work fine on both of those. I use these all over the place, in most of my projects I never change from the default .NET 2.0 Subset, and I have never seen this error.

I suspect this is somehow coming from the editor you're using, rather than from Unity. Try closing MonoDevelop or VisualStudio or whatever. Edit your script (if needed) with a simple text editor, like Notepad on Windows or TextWrangler on the Mac. Save it and switch back to Unity. I bet it works.

And then get Script Inspector 3, and wonder how you ever got by without it!

 

I'm confused about you saying that you can only use .NET2.0. Since I see many options under ProjectSettings>Editor.

Also, I went to project settings in Unity and changed to .NET 4.0 Framework and I can now use default parameters... You think I should use .NET 2.0 instead?

 

I'm talking about Project Setting > Player, "API Compatibility Level":


I don't have anything like that under Project Settings > Editor:


And yeah, I usually use .NET 2.0 Subset, unless I'm doing something that requires the full .NET 2.0 (like reflection). This is in Unity 5.3. Can you show me what you're talking about?

 

ProjectSettings>Editor .... is incorrect sorry!!! ...I meant, in MonoDevelop, I was going to Project>Assembly-CSharpOptions>General.

Here are all the .NET versions from 2.0 up to 4.6

I just tried switching to different versions, but I still cannot get Default Parameters working.(ignore that I said 4.0 worked for me).

 

Well there's your problem. I already suggested you quit using MonoDevelop and try a text editor (or better yet, Script Inspector 3) instead.

What you're observing is a MonoDevelop problem, not a Unity problem. (Though it's still odd, because until recently I used MonoDevelop too, and I never had this issue.)

 

No idea what you have broken.

But for a dirty fix you can always do it old school. Before default parameters were a thing there was overloading.

Code (CSharp):

1. void SomeMethod () {
2.     SomeMethod (false);
3. }
4.  
5. void SomeMethod (bool something){
6.     // do something
7. }