how to achieve polymorphism in java

Java Implementation of Polymorphism Basic knowledge Review Polymorphism, that is, overloading and rewriting. the overload occurs in a class. override occurs in the subclass, which means that the subclass overrides the method with the same name as the parent class. just learning the language doesn't have to be so clear. You only need to know how to use it. If you

Public Static voidMain (string[] args) { at NewRoundglyph (5); - } -}Output:Glyph () before draw ()Roundglyph.draw (). Radius = 0Glyph () after draw ()Roundglyph.roundglyph (). RADIUS = 5Why is this output? This requires a clear understanding of the order in which constructors are called in Java?(1) initialize the storage space allocated to the object into binary 0 before anything else occurs;(2) call the base class constructor. Recu

Reference and excerpt from: http://www.runoob.com/java/java-polymorphism.htmlPolymorphicPolymorphism is the ability of a behavior to have many different forms of expression.Polymorphism is the same interface that uses different instances to perform different operations.Three prerequisites for polymorphic presence:1. Inheritance 2. Rewrite 3. Parent class reference to child class objectsuch as parent a = new

Override after Java5 onward { return new Dog ();}}Dog is a sub type of animal, therefore different return type are OK heredifference between overloading and overriding Method Overloading Method overriding Parameter must is different and name must be same. Both name and parameter must be same. Compile time polymorphism. Runtime polymorphism

program does not need to retrieve the method table at run time, can improve the efficiency of code execution. In Java, methods that are modified by static or private are implicitly declared final, because dynamic binding has no meaning.Because dynamic binding consumes resources and is not necessary in many cases, some programmers think that unless there is sufficient reason to use polymorphism, all methods

alsoIt is the carding of their own knowledge to supplement. That's why I'm here. (Mamma Mia, it seems to run away ...) ） Inheritance of ClassesSyntax rules:Class Subclass extends Parent classNote: 1, the parent class type is public, protected, and default when the tragic inheritance.2. In Java, subclasses can inherit only one parent class.3. All Java classes are subclasses of object.4. The Super keyw

subclass, which I will summarize (upward transformation ): 1. If a field with the same name is a parent class.2. If the subclass overwrites the method of the parent class, the subclass method is called.3. If the parent class does not have a subclass-defined method, the compilation will be incorrect.Ah, the result is clear.Can you help me understand this sentence: the object type is determined by the class that creates it, rather than the variable that declares it. If so, isn't the Son class obj

Java object-oriented polymorphismPolymorphism Performance in Java:1, overloading and rewriting of methods (overwrite);2, the parent class can be used to point to the specific implementation of subclasses, and can be changed at any time to other subclasses of the specific implementation;Let's start with a parent class animal:1 Package Com.java1234.chap03.sec13; 2 3 Public class Animal {4 5 Public v

Polymorphism:---The various morphological essence of an object: the reference of the parent class points to the subclass object---Premise: there must be an inheritance or implement class Animal{}class dog extends Animal{}main{dog d = new Dog ();//Native Animal dog = new Dog (); Polymorphic} Note: objects created by polymorphic forms can only access member methods that are common to the child parent class, and the result is a subclass-specific member m

1. Using inheritance to develop superclass (superclass)2. Use super keyword to evoke super class construction method3. Overriding methods in Super-class4. Distinguish between override and overload5. Explore the ToString () class in the object class6. Discovery of polymorphism and dynamic binding7. Describe why it is necessary to interpret the downward transition8. Explore the Equals method in the object class9. Storage, retrieval, implementation of Ar