What are the pitfalls of a Java noob? [closed]

Answer 1

I would have to say.

One of most common noob pitfalls phrases like "parameters on methods are always passed as reference, because Object variables are references, right?"

so when you see something like:

public void foo(String str){
      str="yeah, this should work!";
}

String str = "";
foo (str);

System.out.println(str);

You can hear a "Wait, WTF !" coming from a noob.

In my experience, java noobs don't know about StringBuffer / StringBuilder. Neither on inmutable objects.