How to make build for some platform when scripts include code for other

I am developing a cross-platform game that can be run on android, ios and webplayer. I am using AndroidJavaObject and AndroidJavaClass in my scripts. The issue is that I can make a build for android but when I try making build for web player it gives errors like
error CS0246: The type or namespace name `AndroidJavaObject' could not be found. Are you missing a using directive or an assembly reference?
and
BCE0021: Namespace 'UnityEngine.AndroidJavaObject' not found, maybe you forgot to add an assembly reference?

I can not go commenting the code each time I make the build for different platforms. Please suggest the solution to this problem.

 

Check this out: https://docs.unity3d.com/Documentation/Manual/PlatformDependentCompilation.html

 

Thanks angrypenguin
This was exactly what I was looking for.

 

me too! good penguin... here's a fish }=]•>