super collapse ii

this:First, call another constructor using this (parameter list). This is only used in the constructor of the class and cannot be used in other places.2. When the name of a function parameter or local variable in the function is the same as that of a member variable, the member variable is blocked. To access the member variable, you must use "this. to reference member variables. Of course, without the same name, you can directly use the name of the member variable instead of this. If you use th

Original address: https://www.cnblogs.com/hasse/p/5023392.htmlThese days to see the class in the inheritance will use this and super, here do a little summary, with you to communicate, there are errors please correct me ~ThisThis 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 broadly divided into 3 types in Java:1. Normal Direct referencesThis does not have

The article turns from @implementation Son:father -(ID) init{ self = [super init]; if (self) { } return self; } This is an ordinary to initialization method that invokes the Init implementation of the parent class before the subclass implements initialization. Based on this initialization method, we compare the self and Super keywords from three aspects. what self is and what

Python: super Getting started with super () In class inheritance, If you redefine a method, this method will overwrite the method of the same name as the parent class, but sometimes we want to implement the function of the parent class at the same time, we need to call the method of the parent class, which can be implemented by using super, for example: Class Ani

------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

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 broadly divided into 3 types in Java:1. Normal Direct referencesThis does not have to be said, this is equivalent to pointing to the current object itself.2. The name of the member who participates in the membership is distinguished by this:Class Person { private int: age = ten; Public person () { System.out.println ("Initialization Age:" +ag

Ext: 52205961The Python language has similar class inheritance to C + +, in which Python customizes the first self, like the this pointer in C + +, to the object itself.Examples of simple Python classes:[Python]View PlainCopy >>> class Hello (object): ... def print_c (): ...print"Hello world!" >>> hello (). Print_c () Hello world! Of course, in practice, the inevitable need for class inheritance, subclasses inherit the parent class, normal as follows:[Python]View

The Python language has similar class inheritance to C + +, and in the class definition, Python customizes the first self, similar to the this pointer in C + +, pointing to the object itself. Examples of Python simple classes: >>> class Hello (object): ... Def print_c (): . print "Hello world!" >>> hello (). Print_c () Hello world! Of course, in practice, the inevitable need for class inheritance, subclass inherits the parent class, normal as follows: >>> class Child (Hell

.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