How will you define method overriding? Can someone mention some of the rules of the overriding method? What methods cannot be overridden? What are Overriding and synchronized/strictfp methods? What is one of the most powerful techniques for code to reuse?
Destructor Definition: A destructor is called when an object exits scope or is explicitly destroyed by a delete call. A destructor has the same name as the class and is prefixed by a tilde. The destructor for the String class, for example, is declared as String. If you don't declare a destructor, tRead more
Destructor Definition:
A destructor is called when an object exits scope or is explicitly destroyed by a delete call. A destructor has the same name as the class and is prefixed by a tilde.
The destructor for the String class, for example, is declared as String.
If you don’t declare a destructor, the compiler will create one for you; for most classes, this is enough. When the class stores handle system resources that must be relinquished or pointers that own the memory they point to, you just need to create a custom destructor.
Destructors are functions with the same name as the class but with a tilde before them.
The declaration of destructors is governed by several rules:
- Accept no arguments.
- Please don’t return a value (or void).
- It is not possible to declare it as const, volatile, or static. They can, however, be used to destroy things that have been defined as const, volatile, or static.
It is possible to declare it as virtual. You can destroy objects without knowing their type by utilizing virtual destructors; the virtual function mechanism calls the correct destructor for the object. For abstract classes, destructors can also be defined as pure virtual functions.
Destructors are a type of destructor that is used to destroy anything.
When one of the following events occurs, destructors are invoked:
- A block-scoped local (automatic) object falls out of scope.
- The delete operator is used to explicitly deallocate an object allocated with the new operator.
- A transient object’s work life span expires.
- When a program is finished, global or static objects are created.
- The destructor is invoked explicitly by using the fully qualified name of the destructor function.
- Destructors have full access to class member functions and data.
- The employment of destructors is subject to two limitations:
- You are unable to obtain its location.
- Derived classes don’t inherit their base class’s destructor.
Destruction order:
When an item is removed from the scope or deleted, the following series of actions occur:
- The class’s destructor is called, and the destructor function’s body is executed.
- Nostratic member object destructors are called in the order they appear in the class declaration. The order in which these members are built or destroyed is unaffected by the optional member initialization list used in their construction.
- Non-virtual base class destructors are called in the reverse order of declaration.
- Virtual base class destructors are called in the order in which they were declared.
Method Overriding Definition: The state of overriding lets a subclass or child class specify a specific implementation function that is already sent by one of its super classes or parent classes in any object-oriented programming language. When a subclass's method has a similar name, value, area, orRead more
Method Overriding Definition:
The state of overriding lets a subclass or child class specify a specific implementation function that is already sent by one of its super classes or parent classes in any object-oriented programming language. When a subclass’s method has a similar name, value, area, or sign, and return type(or sub-type) as a method in its superclass, the subclass’s method is said to override the super-method class’s.
One way that Java gets Runtime Polymorphism is by method overriding. However, the child class’s version is used when a method is applied using an object from a subclass. In other words, the version of an overridden method that gets performed is determined by the type of the object being referenced to, not the type of the reference variable.
Overriding method rules are as given below:
To avoid a compile-time error, derived concrete classes must override abstract methods in an interface or abstract class.
Overriding and synchronized/strictfp methods:
The availability of a synchronized/strictfp modifier with a technique has no influence on the overriding rules, which means a synchronized/strictfp technique can override a non-synchronized/strictfp method and vice versa.
Overridden methods enable Java to provide polymorphism at runtime, as previously indicated. Polymorphism is important in object-oriented programming because it allows a generic class to declare methods that will be shared by all of its descendants while allowing subclasses to define the specific implementation of any or all of those methods. Java states the “one interface, various methods” element of polymorphism in various ways.
Methodology Dynamic Object-oriented design’s dispatch mechanism is one of the most powerful code reuse and robustness techniques. The method to use existing code libraries to call methods on new class instances without recompiling while keeping a clean abstract interface is a tremendously valuable feature.
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