I have been working in Android Studio for about a year, and just recently found out that there is such a program - Xamarin. In this program, you can write simultaneously for Android, iOS and WP.
How optimized is the application after compilation in this program? For example, I wrote a program in AS and exactly the same in Xamarin. Will programs have a big difference in the occupied place, the consumption of RAM? All the same, AS was originally made for writing applications on Android, and Xamarin somehow translates the code itself.
In which language is it better to write - Java or C #?