shell script seven: if structure conditional sentence knowledge and Practice

7, Knowledge and practice of if structure conditional sentence (1) if conditional single and double branch syntax 1. Single branch if condition then instructions fi 2. Bifurcate if condition then instructions else Instruction set 2 fi (2) if conditional multi branch statement 1. Structure of statement if condition 1 then ...

Added by crishna369 on Wed, 29 Apr 2020 17:46:38 +0300

Source code interpretation of golang slice

This paper studies the creation, expansion and implementation of deep copy of golang slice from the perspective of source code. Internal data structure slice has only three fields, among which array is the part to save data, len field is the length and cap is the capacity. type slice struct { array unsafe.Pointer // Data section len in ...

Added by christine75 on Sun, 26 Apr 2020 12:40:56 +0300

Python 0 basic development game, ground mouse (detailed tutorial)

  1, Preparations 1 download and install python2 download and install VS code EditorWhen installing, please check add to path   3 install pygame moduleNote: many people will encounter various problems in the process of learning python, and no one will help answer the questions. For this reason, I have built a python full stack fr ...

Added by beboo002 on Tue, 21 Apr 2020 06:42:53 +0300

[original] quick start to golang [9.3] - profound slicing skills

Preface What will the following program output? package mainimport "fmt"func f(s []string, level int) {        if level > 5 {               return        }        s = append(s, fmt.Sprint(level))        f(s, level+1)        fmt.Println("level:", level, "slice:", s)}func main() {        f(nil, 0)} Its output is: level: 5 slice: [0 1 2 3 4  ...

Added by tripc1 on Mon, 20 Apr 2020 14:13:45 +0300

Details of Javax Validation verification architecture

You're still using if else... Check the parameters from the front end? Are you still checking parameters with code? If so, your project verification is not perfect. Xiaobian here shares the parameter verification through annotation, farewell to if else... The era of!!! This article mainly introduces Javax ValidationI annotation verification ar ...

Added by GM on Sat, 18 Apr 2020 12:53:26 +0300

The 44th blog post of Xiao Liu

Today, I want to have an early rest. There are so many things at home. I really don't want to study hard these days. However, there are so many things waiting to be done by myself. I still can't study at home. Maybe I drink too little chicken soup. <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> & ...

Added by Chalks on Tue, 14 Apr 2020 19:10:47 +0300

R-Breaker Strategy for Commodity Futures

1. Summary The R-Breaker strategy was developed by Richard Saidenberg and published in 1994.After that, it was ranked one of the top 10 most profitable trading strategies by Futures Truth magazine in the United States for 15 consecutive years.Compared with other strategies, R-Breaker is a combination of trend and reversal.Not only can you capt ...

Added by maltech on Thu, 09 Apr 2020 06:00:53 +0300

Use of classes (classes and objects, constructors and destructors)

Recent Studies on Classes and Objects I'm good at rowing. I didn't listen to classes. It's harmful, so it's a bit cloudy. So write this blog to understand.   The use of a class is like encapsulating something, defined as a class The place and structure defined are actually a little similar. It doesn't feel like much in the algorithm. Never touc ...

Added by Ting on Sun, 05 Apr 2020 22:59:27 +0300

Interpretation of HashMap source code (1)

1. Preface                               . Let's start reading the source code of HashMap. 2. Inheritance and implementation of HashMap classes public class HashMap ...

Added by Andy-H on Sun, 05 Apr 2020 21:45:04 +0300

ios local various paths, cache, etc

Caching images locally is used in many scenarios. If only storing file information, it is convenient to build a plist file or database to solve the problem, but it is not so convenient to store images in sandbox. Here are two simple ways to save pictures to sandbox. 1, Save the image as a base64 string in the database o ...

Added by yaron on Sun, 05 Apr 2020 13:34:35 +0300