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kotlinlang

I learnt basic Java and migrated directly to kotlin(new comer) but the problem comes most documentation, libraries and snippets are almost written in Java so it's pain and I know kotlin to Java converter exists , i sometimes think of going back to Java can some help me out regarding the issue 

There is no particular issue here. Java won't go away soon and you'll see a lot of Java code snippets in the future (also in other languages). If it bothers you for some reason than maybe yes, stick to what you know better.

I would say, it depends on your development target if you should go with kotlin or java.
So most of the android documentation by google is already available for java AND kotlin on their website <http://d.android.com|d.android.com>
For Web development it depends on the framework you want to work with. There are kotlin based ones like ktor (<http://ktor.io|ktor.io>) but also java based ones like spring (<http://spring.io|spring.io>)
Most Java frameworks already announced their support for kotlin but the documentation is not “refurbished” yet.