Difference between creating an instance variable and creating a new object in Java?

Question

I understand the difference between creating an object and creating a variable. For example:

private int number;
MyClass myObj = new MyClass();

Answer 1

A class is a type. Java is a strongly typed language, so most of the time it needs to know the types of the things it is dealing with.

A reference variable simply holds a reference to an object. Because Java is strongly typed, it always wants to know the type of the reference that a variable is holding (i.e., since a class is a type, it wants to know the class of the object that a variable's reference points to).

whatEver object1 = new whatEver();

1. declares a reference variable (object1) and that its type is whatever
2. creates a new() object of type whatever
3. assigns the reference for the new whatever object to the reference variable object 1
4. the assignment is valid because the type of the object and the type of the variable agree

Next is...

private MusicPlayer player;
player  = new MusicPlayer();

The above accomplishes a similar result, but in multiple steps. The 1st line only establishes that the variable player will hold a reference to an object of type MusicPlayer. Java always wants to know the types of things before they are used.

The second line creates a new() object of type MusicPlayer and assigns its reference to variable player. The assignment is, again, valid because the type of the object and the type of the reference variable agree.