Terms

Question 1

What is a runtime instance of a class?

Answer 1

An object

Question 2

An object contains what of the instance variables declared by its class and what to the methods of the class?

Answer 2

In-memory copy and pointers

Question 3

What is the procedure to create an object?

Answer 3

Allocation and initialization

Question 4

What two distinct pieces specify a class?

Answer 4

The interface and the implementation

Question 5

Where does the class declaration and definitions for the public interface go?

Answer 5

The interface

Question 6

Which file extension has the class, type, function and constant declarations in them?

Answer 6

The header files (.h)

Question 7

Which file extension has the implementation in them and may contain Objective-C and C code in them?

Answer 7

The implementation files (.m)

Question 8

Which file extension has the implementation in them and may contain Objective-C, C, and C++ code in them?

Answer 8

The implementation files (.mm)

Question 9

What compiler directive insures that that the same file is never included more than once?

Answer 9

import

Question 10

What file in a framework is best to import, and what is usually that filed named?

Answer 10

The framework's umbrella file and is usually the same name as framework; e.g., the syntax for importing the header files of the (hypothetical) Gizmo framework is:
#import

Question 11

A class declaration begins and ends with what compiler directives?

Answer 11

@interface and @end

Question 12

What is the class name and what is the parent class name in the following syntax:
@interface ClassA : ClassB
@end

Answer 12

ClassA is the class name and ClassB is the parent class

Question 13

True or False. An Objective-C class can have more than one parent.

Answer 13

False. In Objective-C, a class can have only one parent.

Question 14

What are the only two types of declarations that can be in a class declaration?

Answer 14

Property and method declarations

Question 15

Where do any class declarations of custom functions, constants, or data types go in the interface file (.h)?

Answer 15

Outside of the @interface…@end block.

Question 16

A class implementation begins and ends with what compiler directives?

Answer 16

@implementation and @end

Question 17

What should an implementation file always import as part of its first lines of code?

Answer 17

It’s interface file.

Question 18

What are the two types of variables that will contain an object that are supported in Objective-C and how are they declared?

Answer 18

Static variable declarations include the class name.
Dynamic variable declarations use the type 'id' for the object.

Question 19

What must go in front of all statically typed object variables and what does it represent?

Answer 19

An asterisk, which represents a pointer declaration.

Question 20

True or False. An ‘id’ object variable type implies a pointer.

Answer 20

True.

Question 21

What do you send to an object to call a method of that object?

Answer 21

A message

Question 22

What is another way to say that you are sending a message to an object?

Answer 22

Messaging

Question 23

What are the two types of methods in Objective-C?

Answer 23

Instance and class methods

Question 24

Which type of method is a method whose execution is scoped to a particular instance of the class?

Answer 24

Instance method

Question 25

Which type of method is a method whose execution is scoped to a method’s class?

Answer 25

Class method

Question 26

True or False. You can call an instance method before you create an instance of the class.

Answer 26

False. You must first create an instance of the class and then message that instance method through that instance.

Question 27

True or False. A class method does not require an instance of an object to be the receiver of a message.

Answer 27

True.

Question 28

Fill in the missing component of a method declaration.
The declaration of a method consists of the method type identifier, a return type, one or more what, and the parameter type and name information.

Answer 28

Signature keywords

Question 29

The minus sign (-) precedes what type of method?

Answer 29

Instance method

Question 30

The plus sign (+) precedes what type of method?

Answer 30

Class method

Question 31

What is a method’s actual name?

Answer 31

A concatenation of all the signature keywords, including colon characters.

Question 32

What does the colon characters in a method declaration declare the presence of?

Answer 32

A parameter

Question 33

True or False. If a method has no parameters, you still put a colon character after the first and only method signature keyword.

Answer 33

False. You omit the colon character for no parameters.

Question 34

Although the phrase “sending a message” is commonly used as a synonym for “calling a method,” what does the actual sending?

Answer 34

The Objective-C runtime.

Question 35

What is required of the runtime to dispatch a message?

Answer 35

A message expression

Question 36

What is used in a message expression to enclose the message?

Answer 36

Square brackets ([ and ])

Question 37

What does the first keyword just inside the leftmost bracket in message expression designate?

Answer 37

The object receiving the message or to whom the message is being sent to

Question 38

What does nesting message expressions help avoid?

Answer 38

Declaring numerous local variables to store the results from each of the message expressions

Question 39

What is notation syntax is used for invoking accessor methods?

Answer 39

Dot-notation.

Question 40

What do accessor methods get and set of an object?

Answer 40

Their state

Question 41

What is key to the an object’s encapsulation?

Answer 41

Their accessor methods

Question 42

What do accessor methods provide to all instances for accessing that state?

Answer 42

A common interface

Question 43

True or False. You cannot use a reference to a dynamically typed object (type of id) in a dot-notation expression.

Answer 43

True.

Question 44

What is required to message a class itself?

Answer 44

A class method

Question 45

What type of object is a class created by the runtime?

Answer 45

Type Class

Question 46

A factory method creates a new instance of the class or is used for accessing some piece of shared information associated with the class. What type of methods are these often used factory methods?

Answer 46

Class methods

Question 47

A property the the general sense is some data what or what by and object?

Answer 47

Encapsulated or stored

Question 48

A property is either an attribute—such as a name or a color—or a what to one or more other objects?

Answer 48

Relationship

Question 49

Accessor methods provide the what and what actions that enable users of an object access to the encapsulated properties?

Answer 49

Get and set

Question 50

True or False. A “getter” accessor method, which returns the value of a property, has the same name as the property.

Answer 50

True.

Question 51

True or False. A “setter” accessor method, which sets a new value for a property, has the same name as the property.

Answer 51

False. A “setter” accessor method has the form setPropertyName:, where the first letter of the property name is capitalized.

Question 52

What does the acronym KVC stand for and what does it do?

Answer 52

Key-value coding, which is a mechanism for accessing an object’s properties indirectly through their names.