I was until now programming in C, which is a very basic language. But now as I am studying data structures, my online teacher actually uses some methods like leftChild(), rightChild(), etc.
But then I started searching whether tree ADT and such are implemented in C++, Python, Java 
by default. And mostly the answers were no.
I just want to confirm whether any language supports tree ADT by default that means without downloading their classes separately.
These are the basic ADTs. I think you should first learn and code them yourselves before jumping into any library with these inbuild features.
Thanks
built in Abstract Data Types in c++/python/java