How to solve all starting problems of android studio

This tutorial is all about How to solve all starting problems of android studio.
This is a simple step and provable the best and easy step even made.

Android Studio Problems:

1. R can not be resolved to a variable :
2. junit:junit:..... errors :
3. javax... errors :
4. sdk errors :

Solution:

Sometimes when starting any android project can't work perfectly in your computer. In that case you may be see the errors and can't solve these problems. And I've found a great solutions for all of these problems.

First If everything not Ok, then just open your Internet connection and click Sync Now and after a minute all necessary plugins will be installed from internet and your app won't see any error. 

So, if you only Sync then, it may not work but if you connect your PC to internet your all problems will be solved quickly and its guaranteed.

Since, if you face any problem, comment please and I'll try to help you.