Module 13: Classes - Quiz

Q: You need to create inheritance within the classes. Which will best complete this statement?


class dbfmTruckVehicleEntry __________ dbfmVehicleEntry

A. void
B. return
C. extends
D. super

Correct Option: C
Explanation:

Justification:

The void keyword is only used with methods. This indicates that a given method does not return a value.
The return keyword is not a valid keyword to be used with classes.
The extends keyword is used in the class declaration to determine which class the given class is extending or inheriting from.
The super keyword is called within a method and indicates whether or not to call the method of the same name from the parent class.

Related Lesson: Class Inheritance

Q: What does the following X++ code snippet achieve?


void new(real _x = 10, real _y = 10)
{
    x = _x;
    y = _y;
}

A. It defines a method called "new" that initializes variables x and y to default values of 10 each.
B. It creates a constructor named "new" with parameters _x and _y, and initializes variables x and y with the provided values.
C. It defines a default constructor that initializes variables x and y to the values of _x and _y.
D. It declares a class with default values of 10 for variables x and y, which can be accessed using the "new" method.

Correct Option: B
Explanation:

It creates a constructor named "new" with parameters _x and _y, and initializes variables x and y with the provided values.
Explanation: In X++, the code defines a constructor named "new" with optional parameters _x and _y. This constructor is used to initialize the values of the variables x and y when an object of the class is created. If no values are provided, the default values of 10 are used.

Q: You are to complete the code needed to create methods in a class with inheritance. You would like your method accessible to any class in the system. Which will best complete this statement?


____ void getFromDialog()
    {
  ~~~Body of code ~~~
        super();
    }

A. public
B. private
C. protected
D. void

Correct Option: A
Explanation:

Justification:

The public keyword is used to make the given method accessible from any other class in the system.
The private keyword only allows access from within the scope of the given method. This prevents accidental or unintentional re-use.
The protected keyword allows access to any subclasses that may extend the class that the method resides in. However, it prevents access from all other outside object calls.
The void keyword is already explicitly stated in the code snippet, and should not be used twice. This indicates that the given method does not return a value. The void keyword is used in conjunction with the scoping keywords: private, public and protected.

Related Lesson: Best Practices

Q: You want to update a record in your SampleTable table that contains the account number 1234 by using the update method. Before you call the update method, which clause is used at the beginning of this statement to locate the record sampleTable.AccountNum == “1234”?

A. where sampleTable.AccountNum == “1234”
B. locate sampleTable.AccountNum == “1234”
C. join sampleTable.AccountNum == “1234”
D. forUpdate sampleTable.AccountNum == “1234”

Correct Option: A
Explanation:

A. Correct: A where clause is used to specify a condition that the update method will test as it processes each row of the SampleTable table.
B. Incorrect: The locate clause doesn’t exist in coding for finance and operations apps.
C. Incorrect: A join clause links two tables on a column that is shared by both tables. It doesn’t locate a specific record.
D. Incorrect: The forUpdate clause is used to specify the table, not a record that you'll be updating.

Q: What methods can you extend to use Chain of Command?

A. Methods declared with the keyword final
B. Private methods
C. Protected and public methods
D. Methods tagged with the attribute hookable(false)

Correct Option: C
Explanation:

A. Incorrect: Final methods cannot use Chain of Command.
B. Incorrect: Private methods cannot use Chain of Command.
C. Correct: Protected and public methods can use Chain of Command.
D. Incorrect: Methods with the hookable attribute set to false cannot use Chain of Command.

Q: Identify valid class name from below

A. <pre class = "prettyprint"><xmp>internal final class +MyClassName{ }</xmp></pre>
B. <pre class = "prettyprint"><xmp>internal final class MyClassName{ }</xmp></pre>
C. <pre class = "prettyprint"><xmp>internal final class 1MyClassName{ }</xmp></pre>
D. <pre class = "prettyprint"><xmp>internal final class MyClassName{ }</xmp></pre>

Correct Option: D
Explanation:


internal final class MyClassName{  }

Q: Which method will allow the method to be called from anywhere that its class is accessible?

A. A public method
B. A private method
C. An access method
D. A protected method

Correct Option: A
Explanation:

A. Correct: Methods that are declared as public can be called from anywhere that the class is accessible.
B. Incorrect: Methods that are declared as private can only be called from methods within the same class.
C. Incorrect: An access method doesn’t exist in finance and operations apps.
D. Incorrect: Methods that are declared as protected can only be called from methods in the class or methods in a subclass of the class.

Q: By default Instance fields are ?

A. protected
B. public
C. static
D. private

Correct Option: A
Explanation: protected

Q: TRUE or FALSE. If a child class inherits methods from a parent class, those methods cannot be overridden or changed in the child class.

A. True
B. False

Correct Option: B
Explanation:

Justification:

False: This statement is false. A child class that inherits methods from a parent can override the inherited methods.

Related Lesson: Class Inheritance

Q: You need to instantiate a class. Which will best complete this statement?


dbfmVehicleEntry vehicleEntry = __________ dbfmVehicleEntry();

A. instantiate
B. new
C. public
D. return

Correct Option: B
Explanation:

Justification:

Instantiate is not a valid keyword.
The new keyword is used to instantiate a class.
The public keyword is used to determine the scope and accessibility of a method, and is not used in instantiation of classes.
Return is not a valid keyword to instantiate a new class.

Related Lesson: Create a Base Class

Module 13: Classes - Quiz

You need to create inheritance within the classes. Which will best complete this statement? class dbfmTruckVehicleEntry __________ dbfmVehicleEntry

What does the following X++ code snippet achieve? void new(real _x = 10, real _y = 10) { x = _x; y = _y; }

You are to complete the code needed to create methods in a class with inheritance. You would like your method accessible to any class in the system. Which will best complete this statement? ____ void getFromDialog() { ~~~Body of code ~~~ super(); }

You want to update a record in your SampleTable table that contains the account number 1234 by using the update method. Before you call the update method, which clause is used at the beginning of this statement to locate the record sampleTable.AccountNum == “1234”?

What methods can you extend to use Chain of Command?

Identify valid class name from below

Which method will allow the method to be called from anywhere that its class is accessible?

By default Instance fields are ?

TRUE or FALSE. If a child class inherits methods from a parent class, those methods cannot be overridden or changed in the child class.

You need to instantiate a class. Which will best complete this statement? dbfmVehicleEntry vehicleEntry = __________ dbfmVehicleEntry();

You need to create inheritance within the classes. Which will best complete this statement?

What does the following X++ code snippet achieve?

You are to complete the code needed to create methods in a class with inheritance. You would like your method accessible to any class in the system. Which will best complete this statement?

You need to instantiate a class. Which will best complete this statement?