What is the difference between an interface and an abstract class?
The only difference I can see is that all methods in an interface are abstract, while abstract class can contain both concrete and abstract methods.

Other than that and the syntax, the only real difference is that a class can implement any number of interfaces but can only extend one abstract/non-abstract class.

Can you define fields inside an interface or abstract class, and what would those be used for?

In Java you can only define static fields in an interface.  Any class that implements that interface then gets those fields "for free."  In an abstract class, you can define any field for the exact same reasons you define fields in normal classes.

What the heck does Encapsulation mean?

In OOP, this means that you don't/can't access the internal details (private, or otherwise restricted, fields and methods) of a class.  This is useful because whoever writes a class doesn't have to worry about someone else changing some fields incorrectly and putting it in an invalid state.  It's useful for whoever uses a class because they don't need to worry about changing some fields incorrectly and putting it in an invalid state.  Also, this allows someone to rewrite the class and implement it internally in a completely different way, without breaking compatibility with existing code.

What is the difference between a static method and a non-static method?

Non-static methods have access to a variable called "this" which means they can access all other methods and fields of that class.  Static methods do not have this variable, so they can only access static methods and fields of that class (unless they obtain an instance of that class).  The difference when calling them is:

ClassName.staticMethod();
ClassName objectReference = ...;
objectReference.nonStaticMethod();

Is this an example of an enhanced for loop?

Code: [Select]

String[] maga= {"you", "lost", "the", "game"};
for(String omni:maga}
     System.out.println(omni);

Yes, also known as a for each loop.

It appears so.

All primitive types start with a lowercase letter, and as long as you follow Java naming conventions, all object types start with a capital letter.  You can actually do special things with many of the classes in the package java.lang.  For example, you can say Integer i = 5; and i would be an object.

Technically, it's not a primitive type, but I still kinda like to think of it as one... Idk

(ninja'd)

The big difference between a primitive type like int and an object type like String (or Integer) is that the former simply contains data while the latter contains a reference to an object stored somewhere else in memory. In particular, the == operator used on object types will return whether the two references point to the same object rather than whether they point to identical objects. (This is rather noxious for Integer: Java keeps a cache of low-valued Integer objects so == can appear to work for a while, then stop working once the code starts dealing with numbers greater than 127.)

I think Javadocs are documentation for methods. Not sure, though, so ask someone else.

Okay... I think I get it.
I also have some more questions (our teacher went over topics and we all pretended we knew everything to avoid embarrassment ).
What's a javadoc and everything to do with it?
What's Autoboxing (and will it be on the AP test)?
I took a practice and got 69.3 - a 5 is 60-80. Do you think I'm safe from getting a 4 if I make dumb mistakes?

What? 60-80 out of 100?

Oh
But still, if 60/80 was the minimum for a 5, you'd only need to get 75% correct