static static + package and guide package + access rights + getter and setter + inheritance + super keyword + method rewriting + polymorphism

static static The problem with this graph is how many people it will print as many times and what is the country We can define it as a static variable at the beginning, so that later it will default to the Qing Dynasty for the country column. And the content corresponding to static is shared. […]

C# method (full article – includes: keyword of parameters, method call order, method stack frame and recursive call to realize Fibonacci sequence, etc.)

Directory 1. Basic definition: 1. The basic composition of the method: 2. Basic classification of methods; 2. The use of methods (design and call) 3.var (variable variable) and named parameters var: Named parameters: 4. Variable scope in the method Five. Parameter keywords 1.params parameters (variable parameters) 2.out parameter (output parameter) 3.ref (pass by reference) 6. […]

JAVA concurrent programming – synchronized keyword

Introduction In order to solve the problems of atomicity, visibility and order in concurrent programming, the Java language provides a series of keywords related to concurrent processing, such as synchronized, volatile , final, concurren package, etc. The synchronized keyword can be used as one of the solutions when the three characteristics of atomicity, visibility and […]

Java–Multithreading-Three cases of thread state, thread priority, daemon thread, thread insecurity and synchronized keyword

Java–Multithreading–Three cases of thread state, thread priority, daemon thread, thread insecurity and synchronized keyword Thread status package com.zy.thread; /** *description: Java–Multithreading–Thread Status Observation *@program: basic syntax *@author: zy *@create: 2023-03-22 20:55 */ public class StudyThreadState {<!– –> public static void main(String[] args) throws InterruptedException {<!– –> Thread thread = new Thread(()->{<!– –> for (int i […]

ABAP Help Document (1): 1.1 Keywords

ABAP Help Document 1.ABAP Reference ABAP is developed by SAP to build complex applications in the SAP environment. Three-layer structure: presentation layer, where users use GUI and Web Browser; application layer, composed of many application servers, which are the application execution environment; data layer, composed of database. These three-layer communication components: ICM (Internet Communication Manager) […]