Programmer Group

1, abstract class When defining a class, it is often necessary to define some methods to describe the behavior characteristics of the class, but sometimes the implementation of these methods is uncertain. For example, if an Employee class is defined, its work() method describes work, but their work is different for different positions. For thi ...

to configure 3.1. Core configuration file The MyBatis configuration file contains settings and attribute information that deeply affect MyBatis behavior. The top-level structure of the configuration document is as follows: configuration properties settings typeAliases typeHandlers objectFactory (object factory) plugins environment ...

IO stream 1, IO stream overview and classification IO stream introduction IO: input / outputStream: it is an abstract concept, which is the general name of data transmission. In other words, the transmission of data between devices is called stream, and the essence of stream is data transmissionIO stream is used to deal with data transmissio ...

1 function 1.1 function basis definition def Function name(): Code 1 Code 2 ... call Function name ()Documentation for functions def Function name(): """ Function description document """ View the documentation for the function help(Function name) 1.2 scope of variable local variable The so-called local ...

preface When using an array, remember that the subscript 0 is the first Subscript 0 is the first Subscript 0 is the first!!! I've thought about this sentence for a long time, and I think it's best to put it at the beginning This chapter is mainly about arrays. In actual use, if we want to declare a large number of data of the same data ...

catalogue 1. Operator classification: 2. Arithmetic operators 3. Shift operator 3.1 shift left operator 3.2 shift right operator 4. Bitwise operator 5. Assignment operator 6. Monocular operator   6.1 introduction to monocular operators 6.2 sizeof and arrays //I haven't finished yet! 1. Operator classification: arithmetic ope ...

This article mainly introduces the methods of accessing some custom attributes of python classes and the dynamic attribute setting of classes, that is, python's built-in function setattr(). Custom attribute access What are attributes? Are the following examples a and b attributes? No, they are global variables. An attribute is a member variab ...

5. Write a Java application that outputs all the Greek letters. Tip: Find the first Greek letter α Encoding in Unicode, last Greek letter ω Encoding in Unicode. And then loop through all the characters in this range to get the Greek alphabet public class helloworld { public static void main(String[] args){ for (int i = 945; i ...

Multithreaded Thread Synchronization 1. Methods involved wait (): Once this method is executed, the current thread is blocked and the synchronization monitor is releasednotify(): Once this method is executed, a process being waited is waked up, and if more than one thread is waiting, a higher priority thread is waked upnotifyAll(): Once this ...

IoC What is IoC? IoC is the abbreviation of inversion of control. Note that it is a technical idea. It describes the creation and management of objects. Traditional development methods: for example, if class a depends on class B, it often creates a new object of class B in class A.IoC development method: we don't need to go to the new object ...