ps4 super

------Super keyword------Super Purpose: Access superclass "hidden member variables (whether static or not) and static methods" and "overridden instance methods" in subclasses. The superclass here must be a "direct superclass", the most recent superclass above the subclass.How to use Super:① calls the constructor of the superclass in the subclass construction meth

1. Subclass constructors If you want to refer to super, you must put super in the first place of the function. class Base {base () {System.out.println ("base"); }} public class Checket extends Base {checket () {super ();//Call the constructor of the parent class, be sure to place the first statement of the method System.out.println ("Che Cket "); } public s

1. Constructor of subclass if you want to refer to super, you must put super at the top of the function Copy Code code as follows: Class Base { Base () { System.out.println ("Base"); } } public class Checket extends Base { Checket () { Super ();//Call the Parent class construction method, be sure to place the first statement

Java programming-this and super 8.8 this and super The following describes how to use the this and super keywords. By using the this and super keywords in a program, you can easily reference a lot of content inside the class and understand the implementation principle of object-oriented, it is easier to understand the

.The non-parametric null constructor that the system automatically adds in the parent class is explicitly written out (in order to have the output, add println):[Java]View Plaincopy Class base{ Base () { System.out.println ("base constructor"); } } Class derived extends base{ public static void Main (string[] args) { Derived d=new derived (); } } Output: base constructor, code compiled. From the example, it seems that subclasses can inherit t

First, this usageConcept: This is an object of its own, representing the object itself, which can be understood as: A pointer to the object itself.The usage of this can be roughly divided into three types in Java:　　1. Direct reference to ordinary objects: this corresponds to the current object itself.2. Use this to distinguish between members whose names are duplicate.　classPerson {Private intAge = 10; PublicPerson () {System.out.println ("Age of Initialization:" +Age );} Public intGetage (int

use super in the JAVA class to refer to the composition of the parent class, using this to refer to the current object. If a class inherits from another class, we will have a parent class object in the subclass object when we new the instance object of the subclass. How do you refer to the parent object inside? Using Super to refer to, this refers to a reference to the current object, and

I recently encountered some questions about super when I was studying java. At first I saw that super had no idea. I found some information and studied it: In Java, sometimes the member variables or methods in the subclass have the same name as the member variables or methods in the parent class. Because the member variables or method names in the subclass have a high priority, the member variables or metho

This article summarizes the usage of super keywords in Java. There is a reference to the parent class object mentioned in the book. (I have a bit doubt about this statement. If it indicates the reference of the parent class object, it should be said as follows: System. out. println (super); can output the representation of the parent class object. However, the above sentence output is incorrect, while Syste

Summary The navigation menu is not necessarily a simple collection of text links, which enriches the level of navigation information and even the hierarchy of the entire site's content. Because the general Pull-down menu has a lot of usability problems, prompting mega Drop-down menu came into being, because this kind of menu is really cow x, so I call it Super Pull-down menu. The related test proves that the Supe