For a full review of Objects read chapter 3 in your book, starting on page 69.
For a more in depth review of attributes and constructors see section 3.4.1 in your book.
For a more in depth review of attributes and constructors see section 3.4.3 in your book.
For a more in depth review of attributes and constructors see section 3.4.2in your book.
Note: I am putting these here because students have asked them in the past, this is not a reflection of what will be on quizzes.
A: A constructor does the set up for the method when it is first created. This usually means setting the initial values for the attributes but it can also include other more complicated code. Importantly the constructor only runs once for ever instance of a class. A method doesn't have as specific of a job, and can be run more than once for each instance of the class. A method also has a return type, a value it gives back to the place it was called, which is something a constructor doesn't have.
A: You can have an array or ArrayList of objects or an object could have an array or Arraylist as one of its attributes.
A: Yes, it could. If the user input the data before the object was created the value could be passed into the constructor as a parameter. After than a method or the constructor could take in user input and set values according to the input that was received or a set method could be used to change the values in an object after user input was received.