In a subclass subl you want to redefine a component of a superclass superl. How do you achieve this? Note: There are 2 correct answers to this question.
Correct Answer: A,C
To redefine a component of a superclass in a subclass, you need to do the following12: You add the clause REDEFINITION to the component declaration in the subclass. This indicates that the component is inherited from the superclass and needs to be reimplemented in the subclass. The redefinition must happen in the same visibility section as the component declaration in the superclass. For example, if the superclass has a public method m1, the subclass must also declare the redefined method m1 as public with the REDEFINITION clause. You implement the redefined component in the subclass. This means that you provide the new logic or behavior for the component that is specific to the subclass. The redefined component in the subclass will override the original component in the superclass when the subclass object is used. For example, if the superclass has a method m1 that returns 'Hello', the subclass can redefine the method m1 to return 'Hi' instead. You cannot do any of the following: You implement the redefined component for a second time in the superclass. This is not possible, because the superclass already has an implementation for the component that is inherited by the subclass. The subclass is responsible for providing the new implementation for the redefined component, not the superclass. You add the clause REDEFINITION to the component in the superclass. This is not necessary, because the superclass does not need to indicate that the component can be redefined by the subclass. The subclass is the one that needs to indicate that the component is redefined by adding the REDEFINITION clause to the component declaration in the subclass.
Question 47
In a subclass subl you want to redefine a component of a superclass superl. How do you achieve this? Note: There are 2 correct answers to this question.
Correct Answer: A,C
Explanation To redefine a component of a superclass in a subclass, you need to do the following12: You add the clause REDEFINITION to the component declaration in the subclass. This indicates that the component is inherited from the superclass and needs to be reimplemented in the subclass. The redefinition must happen in the same visibility section as the component declaration in the superclass. For example, if the superclass has a public method m1, the subclass must also declare the redefined method m1 as public with the REDEFINITION clause. You implement the redefined component in the subclass. This means that you provide the new logic or behavior for the component that is specific to the subclass. The redefined component in the subclass will override the original component in the superclass when the subclass object is used. For example, if the superclass has a method m1 that returns 'Hello', the subclass can redefine the method m1 to return 'Hi' instead. You cannot do any of the following: You implement the redefined component for a second time in the superclass. This is not possible, because the superclass already has an implementation for the component that is inherited by the subclass. The subclass is responsible for providing the new implementation for the redefined component, not the superclass. You add the clause REDEFINITION to the component in the superclass. This is not necessary, because the superclass does not need to indicate that the component can be redefined by the subclass. The subclass is the one that needs to indicate that the component is redefined by adding the REDEFINITION clause to the component declaration in the subclass. References: 1: METHODS - REDEFINITION - ABAP Keyword Documentation - SAP Online Help 2: Redefining Methods - ABAP Keyword Documentation - SAP Online Help
Question 48
Class super has subclass sub. Which rules are valid for the sub constructor? Note: There are 2 correct answers to this question.
Correct Answer: A,C
The sub constructor is the instance constructor of the subclass sub that inherits from the superclass super. The sub constructor has some rules that it must follow when it is defined and implemented12. Some of the valid rules are: * The method signature can be changed: This is true. The sub constructor can have a different method signature than the super constructor, which means that it can have different input parameters, output parameters, or exceptions. However, the sub constructor must still call the super constructor with appropriate actual parameters that match its interface12. * The constructor of super must be called before using any components of your own instance: This is true. The sub constructor must ensure that the super constructor is called explicitly using super->constructor before accessing any instance components of its own class, such as attributes or methods. This is because the super constructor initializes the inherited components of the subclass and sets the self-reference me-> to the current instance12. You cannot do any of the following: * Import parameters can only be evaluated after calling the constructor of super: This is false. The sub constructor can evaluate its own import parameters before calling the constructor of super, as long as it does not access any instance components of its own class. For example, the sub constructor can use its import parameters to calculate some values or check some conditions that are needed for calling the super constructor12. * Events of your own instance cannot be raised before the registration of a handler in super: This is false. * The sub constructor can raise events of its own instance before calling the constructor of super, as long as it does not access any instance components of its own class. For example, the sub constructor can raise an event to notify the consumers of the subclass about some status or error that occurred during the initialization of the subclass12. References: 1: Inheritance and Constructors - ABAP Keyword Documentation - SAP Online Help 2: Using Static and Instance constructor methods | SAP Blogs
Question 49
You are designing the following select statement in ABAP Open SQL: To adhere to the most recent ABAP SQL syntax conventions from SAP, on which line must you insert the "INTO TABLE @gt flights" clause to complete the SQL statement?
Correct Answer: D
Question 50
In this nested join below in which way is the join evaluated?
Correct Answer: C
Explanation The nested join is evaluated from the top to the bottom in the order of the ON conditions. This means that the join expression is formed by assigning each ON condition to the directly preceding JOIN from left to right. The join expression can be parenthesized implicitly or explicitly to show the order of evaluation. In this case, the implicit parentheses are as follows: SELECT * FROM (a INNER JOIN (b INNER JOIN c ON b~c = c~c) ON a~b = b~b) This means that the first join expression is b INNER JOIN c ON b~c = c~c, which joins the columns of tables b and c based on the condition that b~c equals c~c. The second join expression is a INNER JOIN (b INNER JOIN c ON b~c = c~c) ON a~b = b~b, which joins the columns of table a and the result of the first join expression based on the condition that a~b equals b~b. The final result set contains all combinations of rows from tables a, b, and c that satisfy both join conditions. References: 1: SELECT, FROM JOIN - ABAP Keyword Documentation - SAP Online Help
