Module 13: Classes

Justification:

1. The void keyword is used before a method name to indicate that the given method does not return a value.
2. The null keyword is not used for specifying whether a method returns a value or not.
3. Placing the “str” keyword before the method name implies that it will be returning a value of type string.
4. Return is not a valid keyword to be used before a method.

Related Lesson: Create a Base Class

Justification:

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

Related Lesson: Create a Base Class

Related Lesson: Create a Base Class

Justification:

1. Insert is not a keyword, but a method on tables. It is not used to call an override method, but to insert data into a table .
2. Return is not a valid keyword used in inheritance scenarios.
3. The void keyword is used before a method. This indicates that a given method does not return a value. The void keyword is already used before myMethod().
4. Super() is the correct call to ensure that the method of the same name, “myMethod” is called.

Related Lesson: Class Inheritance

Justification:

1. The void keyword is only used with methods. This indicates that a given method does not return a value.
2. The return keyword is not a valid keyword to be used with classes.
3. The extends keyword is used in the class declaration to determine which class the given class is extending or inheriting from.
4. 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

Justification:

1. The public keyword is used to make the given method accessible from any other class in the system.
2. The private keyword only allows access from within the scope of the given method. This prevents accidental or unintentional re-use.
3. 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.
4. 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

Justification:

1. A runnable class is a class that can be used as a startup object in a project. It contains a static main method. The main method is the entry point of your job.
2. A normal class should not be used when testing random code samples
3. A static class is not a valid class
4. A public class implies that the methods from the class can be accessed anywhere. However, to test code, you should use a runnable class that contains a static main method.

Related Lesson: Methods

Justification:

1. A static method is a method that does not require object instantiation, but this does not determine whether or not a value will be returned.
2. A method of type null is not a valid method in Dynamics AX.
3. Void is the keyword used to specify that nothing should be returned from this method.
4. The Private keyword determines the scope or accessibility of a method’s variables and does not determine what, if anything should be returned.

Related Lesson: Methods

Justification:

1. Inherits is not a valid keyword in X++ for class inheritance
2. Extends is the correct keyword to use in the class declaration in order to specify Class Inheritance. For example, “class ChildClass extends ParentClass”
3. Supports is not a valid keyword in X++ for class inheritance
4. Follows is not a valid keyword in X++ for class inheritance

Related Lesson: Class Inheritance

Justification:

1. False: This statement is false. The Private keyword only allows access to variables within the scope of the current class. Subclasses cannot access these variables. The “Protected” keyword should be used to provide access to subclasses as well.

            Related Lesson: Best Practices

Justification:

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

Related Lesson: Class Inheritance

• 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.

• A. Incorrect: A new method is used to create an instance of the class and isn't automatically added to a runnable class.
• B. Incorrect: A static method is used to work with data in a table and isn't automatically added to a runnable class.

• C. Correct: A main method is automatically added to a runnable class. Therefore, you would add a runnable class instead of a class to your project.
• D. Incorrect: A finalize method finalizes the instance of the class. It isn't automatically added to a runnable class.

• 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.

• 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.

• 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.

protected 

internal final class MyClassName{  }