Chapter 7 - Classes and Objects

The format specifier_____is used to output values of type float or double. Which is it? 1. %f 2. %d 3. %s 4. %t

%f

A reference variable that is a reference to an object is used to invoke a method. True or false?

True

Reference-type instance variables are initialized by default to the value null. True or false?

True

Variables or methods declared with access modifier public are accessible wherever the program has a reference to an object of the class. True or false?

True

Gradebook myGradeBook = new Gradebook(); Which is true? 1. a constructor 2. creating an object to reference the class 3. a special method that has to have the same name as the class 4. all of the above

all of the above

When an object of a class maintains its own copy of an attribute, the field that represents the attribute is also known as a(n) _______.

instance variable

Fields (non-static class level variables) are ___ that store data. Which is it? 1. instance variables 2. private variables 3. object variables

instance variables

To use the methods in a class such as Scanner, you first have to ___ an object of the class and use it to call the methods. Which is it? 1. instantiate 2. initiate 3. incriminate 4. inginate

instantiate

The keyword public is an access ______. Which is it? 1. qualifier 2. instance 3. modifier

modifier

Keyword____requests memory from the system to store an object, then calls the corresponding class' constructor to initialize the object. Which is it? 1. public 2. new 3. private

new

Are import declaration required? Which is the right answer? 1. required 2. not required when one class in a package uses another in the same package 3. not required if always refer to a class with its full class name 4. 2 & 3 5. 1 & 3 6. 1 & 2

2 & 3