A super class is a generalization of its subclasses. The subclass in turn is a specialization of its super classes. The assignment of a subclass instance to a reference varia. The widening cast is, as with inheritance, the opposite of the narrowing cast: Here it is used to retrieve a class reference from an interface reference. If it is to be impossible to instantiate a class more than once for example, because it serves as a data administrator or data container , you can use the singleton concept.
A public static component could then make the reference to the class available to an external user. Inherited methods can be redefined in subclasses Redefined methods must be re-implemented in subclasses. The signature of redefined methods cannot be changed Static methods cannot be redefined.
In ABAP Objects, you can not only add new components, but also provide inherited methods with new implementations. This is known as redefinition. You can only redefine public and protected instance methods, other components static methods, attributes and so on cannot be redefined.
Changes to method parameters signature changes are not possible. A component instance is a running component that can be run in parallel with other instances of the same component.
Encapsulation means that the implementation of an object is hidden from other components in the system, so that they cannot make assumptions about the internal status of the object and therefore dependencies on specific implementations do not arise.
Filter Badi- Business Add-Ins may be implemented on the basis of a filter value. If an enhancement for country-specific versions is provided for in the standard version, it is likely that different partners will want to implement this enhancement.
The individual countries can create and activate their own implementation. Global Local Exceptions Class. Protected components Only visible within the class and its sub classes. Methods have a parameter interface called signature that enables them to receive values when they are called and pass values back to the calling program. To go to an address before performing the operation a dereference variable is a pointer to the variable, not the variable itself.
A pointer can be re-assigned any number of times while a reference cannot be reassigned after initialization. Field symbols are similar to dereference pointers. Thus, you can only access the content of the data object to which the field symbol points. That is, field symbols use value semantics. If you want to access the content of the data object, you need to dereference the data reference first. Yes, class can be created without any constructor.
Default constructor will be created when we define a class without constructor. Instance method is available separately in each object instance , static method is global and no instance is required for static method.
Class is user defined data type which contains methods, events, attributes, interfaces etc. Before going to static classes, you should understand static components. Singleton class is a class which allows to instantiate Create Object only. Event is a mechanism by which method of one class can raise method of another class, without the hazard of instantiating that class.
It is a class which contains methods with implementation as well as methods without implementation. Abstract class is a class which contains at least one abstract method.
Abstract class are mainly used for creating inheritance. It is the keyword which indicates the class definition is delayed or postponed or Defined at some place in program. Polymorphism is a concept by which the same method names will behave differently in different classes i. Class based exceptions are more beneficial then classical exceptions. If we have nested function modules and suppose the inner function module has thrown an exception then it will be propagated to the outer function module.
Hence immediately the exception is not handled. Very Nice. Please elaborate by taking one live business example. Skip to Content. Former Member.
May 25, 1 minute read. IF sy-subrc EQ 7. Transparent table holds application data. Pooled tables: Pooled tables in the dictionary has a many-to-one relation with the table in database.
Table in the database has the different name as in the dictionary. Pooled table are stored in table pool at the database level. Terms of Use. SBI Clerk. SBI PO. IBPS Clerk. Forgot Password? Please login or signup to post answers! Please login or signup to post videos! Related Questions. When do we use End-of-selection?
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