Develop Object-Oriented Code MB-500 Practice Questions (Page 7)

Questions 31–35

1. 31foundation · easy

   In X++, what is the purpose of an abstract class?

   • ATo provide a base class that cannot be instantiated and may contain abstract methods
   • BTo hide the implementation details of all methods
   • CTo create a class that can only be used as a singleton
   • DTo define a class that has only static methods
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2. 32application · medium

   A developer is designing a class hierarchy for different types of warehouse workers. All workers have a common `calculatePay` method, but the calculation differs for full-time and part-time workers. The developer wants to promote code reuse and allow polymorphic calls. Which design should the developer implement?

   • ACreate a base class `Worker` with a `calculatePay` method that contains a conditional statement to handle both worker types.
   • BCreate an abstract class `Worker` with an abstract `calculatePay` method, and derive `FullTimeWorker` and `PartTimeWorker` classes that implement the method.
   • CCreate a single `Worker` class with a `workerType` enum and a `switch` statement in `calculatePay`.
   • DCreate two unrelated classes `FullTimeWorker` and `PartTimeWorker` with duplicate `calculatePay` methods.
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4. 33expert · hard

   A developer is debugging a class hierarchy where a base class defines a variable with the same name as a variable in a derived class. The developer notices that the derived class method is using the derived class variable, but the base class method uses the base class variable. What is the reason for this behavior?

   • AThe base class method is using the derived class variable because of inheritance.
   • BX++ does not support variable hiding; this behavior is due to a bug.
   • CThe derived class variable overrides the base class variable in memory.
   • DVariables are scoped to the class where they are declared, so each class uses its own variable.
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5. 34application · medium

   A developer needs to add metadata to a custom class so that it can be discovered by a framework that scans for classes with a specific attribute. The attribute should also be usable on methods. Which action should the developer take?

   • AAdd a comment to the class declaration indicating the metadata.
   • BModify the `SysAttribute` class to include the custom metadata.
   • CCreate a new class that extends `SysAttribute` and apply it to the custom class and methods.
   • DUse the `SysExtension` framework without any attribute.
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6. 35expert · hard

   A developer is designing a class hierarchy for a reporting system. The base class Report has a method generate() that is abstract. Derived classes SalesReport and InventoryReport implement generate(). The developer also needs to add a new report type, TaxReport, that shares some logic with SalesReport but also has unique logic. The developer wants to avoid code duplication. Which approach is best?

   • ACreate an intermediate abstract class SharedReport that contains the shared logic and have both SalesReport and TaxReport inherit from it.
   • BCreate TaxReport as a subclass of SalesReport and override generate().
   • CUse composition by having TaxReport contain an instance of SalesReport.
   • DCreate TaxReport as a subclass of Report and duplicate the shared logic.
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