Question 1

Which of the following statements is false
A) Variables declared in a particular method's body (such as Main) are local variables, which can be used only in that method.
B) Each method can access its own local variables and those of other methods.
C) When a method terminates, the values of its local variables are lost.
D) A method's parameters also are local variables of the method.

Accepted Answer

Each method can access its own local variables and those of other methods.Actually,each method can access its own local variables,but not those of other methods.

Question 2

By default,everything in a class is ________,unless you specify otherwise by providing access modifiers.
a) public
b) private
c) protected
d) None of the above.

Accepted Answer

Actually,the default initial value for string instance variables is null

Question 3

The code
myAccount.SetName(theName);
calls myAccounts's SetName method,passing theName's value as SetName's argument.

Accepted Answer

This statement calls myAccount's SetName method with the argument value of theName.

Question 4

Each class you create becomes a new type you can use to create objects,so C# is a(n)________ programming language.
A) type sensitive
B) flexible
C) elastic
D) extensible

Accepted Answer

extensible

Question 5

Which of the following statements about creating,compiling and running a Visual C# project with two classes is false
A) The IDE automatically recognizes as the app's entry point the class that contains Main.
B) When you select Build > Build Solution in Visual Studio, the IDE compiles all the files in the project to create the executable app.
C) If you do not build the app before running it, typing Ctrl + F5 will build the app first and run the app only if there are no compilation errors.
D) In a given project, declaring a Main method in more than exactly one class results in a runtime error.

Accepted Answer

In a given project,declaring a Main method in more than exactly one class results in a runtime error.Actually,it's a compilation error.

Question 6

Which of the following statements is false
A) Normally, a class also contains methods and properties. These manipulate the instance variables belonging to particular objects of the class.
B) Instance variables are declared inside the bodies of the class's methods and properties.
C) Clients of a class cannot access the class's private instance variables.
D) Clients of a class can access the class's public methods.

Accepted Answer

Instance variables are declared inside the bodies of the class's methods and properties.Actually,instance variables are declared inside a class declaration but outside the bodies of the class's methods and properties.

Question 7

A method such as Main "drives" an object by calling its methods-without having to know how the class's internal mechanisms work.In this sense,the class containing method Main is referred to as a driver class.

Accepted Answer

This statement is true. The Main method in the driver class calls the methods of the object it "drives" without needing to know the inner workings of the class.

Question 8

Consider the code (in class Account):
Public string GetName()
{
Return name;
}
Which of the following statements is false
A) The method returns a particular Account object's name to the caller-a string, as specified by the method's return type.
B) The method has an empty parameter list, so it does not require additional information to perform its task.
C) When a method with a return type other than void is called and completes its task, it must return a result to its caller.
D) All of the above are true.

Accepted Answer

All of the above are True

Question 9

Consider the code:
Console.WriteLine($"Initial name is: {myAccount.GetName()}");
Which method is called first
A) WriteLine
B) GetName
C) They execute at the same time.
D) None of the above.

Accepted Answer

GetName

Question 10

Consider the code:
Public void SetName(string accountName)
{
Name = accountName;// store the account name
}
Which of the following statements is false
A) The first line of each method declaration is the method header.
B) The method's return type (which appears to the left of the method's name) specifies the type of data the method returns to its caller after performing its task.
C) The return type void indicates that when SetName completes its task, it does not return any information to its calling method.
D) A method requires one or more parameters that represent the data it needs to perform its task.

Accepted Answer

A method requires one or more parameters that represent the data it needs to perform its task.Actually,a method also can have no parameters.

Question 11

Most instance variables are declared ________.
A) public
B) protected
C) private
D) None of the above.

Accepted Answer

private

Question 12

The fact that we could create and manipulate an Account object without knowing its implementation details is called ________.This is one of the most powerful software-engineering benefits of object-oriented programming.
A) inheritance
B) shadowing
C) overriding
D) abstraction

Accepted Answer

abstraction

Question 13

An attempt by a method that's not a member of a particular class to access a private member of that class is a runtime error.

Accepted Answer

Actually it's a compilation error.

Question 14

Method ReadLine reads a whole line,including all the characters the user types up to and including the newline that the user typed by pressing Enter.

Accepted Answer

Actually,method ReadLine reads a whole line,including all the characters the user types until the newline that the user typed by pressing Enter-the newline is discarded.

Question 15

Instance variables are required to be explicitly initialized before they're used in a program.

Accepted Answer

Actually,instance variables are not required to be explicitly initialized before they're used in a program-unless they must be initialized to values other than their default values.

Question 16

Which of the following statements is false
A) Each object of a class shares one copy of the class's instance variables.
B) Each class declaration is typically stored in a file having the same name as the class and ending with the .cs filename extension
C) Class, property and method names begin with an initial uppercase letter (i.e., Pascal case); variable names begin with an initial lowercase letter (i.e., camel case).
D) A class has attributes, implemented as instance variables. Objects of the class carry these instance variables with them throughout their lifetimes.

Accepted Answer

Each object of a class shares one copy of the class's instance variables.Actually,each object of a class has its own copy of the class's instance variables.

Question 17

Consider the code:
MyAccount.SetName(theName);
Which of the following statements is false
A) When this method executes, the argument value in the call's parentheses (i.e., the value stored in theName) is copied into the corresponding parameter in the method's header.
B) Each parameter must specify a type followed by a parameter name. When there are multiple parameters, they are placed in a comma-separated list.
C) The number and order of arguments in a method call must match the number and order of parameters in the method declaration's parameter list.
D) All of the above are true.

Accepted Answer

All of the above are True

Question 18

Which of the following statements is false
A) Set and Get methods can validate attempts to modify private data and control how that data is presented to the caller, respectively.
B) If an instance variable were public, any client of the class could see the data and modify it, including setting it to an invalid value.
C) public data allows client-code programmers to write code that depends on the class's data format. If the class's owner changes that format, any client code dependent on it would "break" and would need to be adjusted to the new format, making it subject to break again.
D) All of the above are true.

Accepted Answer

All of the above are True

Question 19

By default,instance variables are not initialized.

Accepted Answer

Actually,every instance variable has a default initial value-a value provided by C# if you do not specify the instance variable's initial value.

Question 20

Making a class's instance variables public and its methods private and accessing those instance variables only through the class's methods and properties facilitates debugging,because problems with data manipulations are localized to the methods (and properties).

Accepted Answer

Actually,making a class's instance variables private and its methods public and accessing those instance variables only through the class's methods and properties facilitates debugging,because problems with data manipulations are localized to the methods (and properties).

Quiz 4: Introduction to Classes,Objects,Methods and Strings

Which of the following statements is false

By default,everything in a class is ________,unless you specify otherwise by providing access modifiers. a) public b) private c) protected d) None of the above.

The code myAccount.SetName(theName); calls myAccounts's SetName method,passing theName's value as SetName's argument.

Each class you create becomes a new type you can use to create objects,so C# is a(n) ________ programming language.

Which of the following statements about creating,compiling and running a Visual C# project with two classes is false

Which of the following statements is false

A method such as Main "drives" an object by calling its methods-without having to know how the class's internal mechanisms work.In this sense,the class containing method Main is referred to as a driver class.

Consider the code (in class Account) : Public string GetName() { Return name; } Which of the following statements is false

Consider the code: Console.WriteLine($"Initial name is: {myAccount.GetName() }") ; Which method is called first

Consider the code: Public void SetName(string accountName) { Name = accountName;// store the account name } Which of the following statements is false

Most instance variables are declared ________.

The fact that we could create and manipulate an Account object without knowing its implementation details is called ________.This is one of the most powerful software-engineering benefits of object-oriented programming.

An attempt by a method that's not a member of a particular class to access a private member of that class is a runtime error.

Method ReadLine reads a whole line,including all the characters the user types up to and including the newline that the user typed by pressing Enter.

Instance variables are required to be explicitly initialized before they're used in a program.

Which of the following statements is false

Consider the code: MyAccount.SetName(theName) ; Which of the following statements is false

Which of the following statements is false

By default,instance variables are not initialized.

Making a class's instance variables public and its methods private and accessing those instance variables only through the class's methods and properties facilitates debugging,because problems with data manipulations are localized to the methods (and properties).