how to achieve polymorphism in java

We used classes to create new types (type), and we used inheritance to facilitate the process of creating classes. I'll delve into the genre in this lecture and introduce the concept of polymorphism (polymorphism). Type checking Any variables and references in Java can be used by type declaration (type declaration). We've seen object data, class data, method pa

The polymorphism of the three main characteristics of object-oriented one. The concept of polymorphismPolymorphism is the three main characteristics of object-oriented after encapsulation and inheritance.Real things often reflect a variety of forms, such as students, students are a kind of people, then a specific Zhang San students are students are also people, that appears two forms.As an object-oriented language,

Below I will take two examples to fully explain the scalability of Java, as a good programmer, you must understand the scalability of the program, very conducive to the development of the program follow-up. First example: Using the computer's motherboard as an example, we are familiar with the computer's motherboard, there is not a lot of modules, network cards, sound cards, want to use these functions, only when the motherboard to run, and then to

Three main features of Java object-oriented:encapsulation: through the Java class to achieve the encapsulation of data and operation methods, the outside world can treat each Java class as a black box, just call the method provided by the black box to complete the operation you want.inheritance: through the inheritance

enum+ polymorphic, I did not say wrong, but Enum is not can be inherited, also can not inherit from others, just can realize interface, what talk about polymorphism?But let's look at the phenomenon first: Java code public enum Fruit {APPLE, PEAR, PEACH, ORANGE; } The above is a simple enum, about which I would like to add:fruit is java.lang.Enum.sub-class, exactly, is a subclass of Enumto il

variable in the class is passed through these getter and setter methods;The This keyword is intended to resolve a conflict with the same name that occurs between the instance variable (private String name) and the local variable (name variable in setName (String name);6. Java Overrides and overloadsRewrite: Subclasses to the parent class to allow access to the method to rewrite the implementation, the return value and parameters can not be changed, t

transformation.A.eat ();What do I do if I want to invoke the cat's unique method?Forces a reference to the parent class. Turn into a subclass type. Downward transformation.Cat C = (cat) A;C.catchmouse ();Never do this by turning the parent class object into a subclass type.What we can convert is that when the parent application points to its own subclass object, the app can be promoted or cast.Polymorphism is a subclass of objects that are changing from beginning to finish.Animal a = new Animal

/*** For each operation in Java, the data type of the operation must be valid. The parent class has a method subclass that has* You can use subclasses to generate objects wherever you can generate objects using the parent class.** Polymorphism* means that objects of different classes are allowed to respond to the same message.* Polymorphism consists of parameteri

mechanisms for object-oriented programming code reuse, and the concept of Java polymorphism can be said to be "an interface, multiple methods." Java implements Run-time polymorphism based on dynamic method scheduling, which is a mechanism for invoking overloaded methods at run time rather than at compile time. The ove

Recent learning of the polymorphism of Java below is a personal arrangement:3 Prerequisites for polymorphic presence :　　1. To have inheritance　　2. To have a method of rewriting　　3. The parent class reference points to the subclass object (for the method defined in the parent class, if the method is overridden in the subclass, then a reference to the parent class type will call this method in the subclass, w

Original: https://www.cnblogs.com/1693977889zz/p/8296595.htmlRecently, it's really important to find the basics. For example, the characteristics of polymorphism in Java, in learning is difficult to understand, more abstract concepts. Learn to be confused, but in the future will find that the foundation in the daily work of understanding occupies an important role.Below, I will use a code instance to recall

various subclasses.The benefits of polymorphism can be naturally elicited here:1, flexible: embodies the flexible and diverse operation, improve the use of efficiency.2, simplification: Unified use of an object to call different subclasses, you can simplify the application software code writing and modification process.There are other benefits as well:3. Replaceable4. Extensibility5, interface.Implementation of p