Programmer Group

1. Exception handling The difference between Error and Exception: Error is a system error that programmers cannot change or handle, such as a system crash, insufficient memory, method call stack overflow, etc. In the event of such an error, it is recommended that the program be terminated. Exception indicates an exception that the progra ...

PS: To reproduce, please indicate the source, I have the copyright. PS: This is based solely on my own understanding. If there is a conflict with your principles and ideas, please understand. Pre-description _This article serves as a backup of my csdn blog's main site. (BlogID=114) Environmental description MLU220 Development Board Ubuntu 18.0 ...

Hardware Chip introduction   WK2204(DataSheet) Is a spi extended UART chip, which implements spi extended 4 routes of uart. The expanded UART channel of the chip has the following features: The baud rate, word length, and check format of each channel can be set independently, providing a maximum communication rate of 2 MbpsEach channel h ...

summary This article mainly uses the Navicat for MySQL tool to analyze the common constraints of the SQL language through programming and code testing: primary key constraints   And foreign key constraints. Each table in the business needs to have one and only one primary key. There can be multiple foreign keys in a table, but ...

DisclaimersThe host penetrated by this article is legally authorized. The tools and methods used in this article are limited to learning and communication. Please do not use the tools and infiltration ideas used in this article for any illegal purpose. I will not bear any responsibility for all the consequences, nor be responsible for any misus ...

Language characteristicsSimple deployment:It can be directly compiled into machine code for executionDo not rely on other librariesRun directly to deployStatically typed languages: hidden problems can be detected at compile timeConcurrency at the language level: it naturally supports concurrency and makes full use of multi-corePowerful standard ...

Java instance – print diamond Outputs a diamond with a specified number of rows. package com.example.yan.java Print graphics; public class Main { public static void main(String[] args) { print(8); // Output 8-line diamond } public static void print(int size) { if (size % 2 == 0) { size++; // Ca ...

Title:   In the old movie "Live and Let Die", there is a plot in which 007 is caught by a drug dealer on an island in the center of an crocodile pool. He uses an extremely bold way to escape - directly stepping on the brain bags of a series of crocodiles in the pool and jumping ashore! (it is said that the stuntman was bitten by ...

1, Small and problems 1. Title Description: In an array, the numbers on the left of each number that are smaller than the current number are added up, which is called the small sum of the array. Find the small sum of a given array. 2. Example: The array is: [1,3,4,2,5] 1 the number smaller than 1 on the left: No 3 the number smaller than ...

1, Foreword This article is mainly based on the learning notes recorded in the official documents and the crazy God Mybatis tutorial. 2, CRUD In the previous article Mybatis learning notes (II): write the first mybatis program based on Maven project The select statement written is as follows: <?xml version="1.0" encoding="UTF-8" ?> &l ...