Both are imperative OOPS. They support classes and objects, and all OOPS features. And you need to learn the same concept in both cases. I am mentioning some of the toughest parts. They support multi-threading, both. And they also support exception handling. And you will find that both languages are different slightly. Also, the syntax of class, objects, inheritance, etc only differs a little. And that is why you can learn both at a time. And with a little more effort, you can learn c++ as well. And in fact, you should first learn C++, and then Java, C# and finally Python.
