Richard Wright
Living Legend
Do I need to learn both of them in depth ?
Ok thanks, I'll bookmark those tutorials then.
That depends on what you want to do. It is part of my programming philosophy to learn problem solving and critical thinking and simply use programming languages as a tool. I will answer this question from a practical perspective.
There are a lot of tools that will do the xml "for you" the xml is basically just a bunch of declarations telling the system what your app needs/will do. The XML is not really that pertinent because it can be abstracted away.
In terms of Java you could exclusively study the java api for the rest of your life and still not master it. The most important thing is understanding what you need to do and using libraries to do anything the code is already out there for. Do not reinvent the wheel by (stupid example) re-writing the HashSet class. Understand the libraries that are out there for doing what you want to do.
I do not know what you are trying to do or your experience level, so "do I need to know something in depth" is tough to answer. Lets see what the other guys say. We all have our own philosophy.