• C example of marking in serial 19 printf


    1、 Tags in printf() 1. introduction to marking sign meaning – The item to be printed is aligned to the left, that is, the item is printed from the left side of the field. Example: “-20s” + If the signed value is positive, a plus sign will be displayed in front of the value; If […]

  • HTML table markup tutorial (14): table headers


    In the HTML language, you can automatically add a title to a table by marking it. In addition, the first row of the table is called the header, which can also be achieved through HTML tags.Basic grammar <TABLE> ….   <TR> <th> Title 1</th><th> Title 2</th><th> Title 3</th><th> Title 4</th><th> Title 5</th>  </TR>  …….. </TABLE> Grammatical interpretationDefine […]

  • Browser working principle and V8 engine


    Browser parsing process When the browser loads HTML resources, the following parsing process will be performed Meet HTML tags and build DOM tree When meeting the style/link tag, call the corresponding parser to process the CSS tag and build the CSS style tree When encountering script tags, call the JavaScript engine to process script tags, […]

  • The stable version of chrome 87 is pushed, and the performance of chrome has been improved the most over the years!


    Today, chrome has updated the latest version of 87, which is the last update of chrome this year. This version is the biggest improvement in chrome performance over the years, and the developer tools have also been greatly updated. Some users think that the performance of chrome has been criticized for a long time. However, […]

  • Uni app using Tencent maps (II)


    Uni app using Tencent maps (I) Locate nearby stores The code is as follows (example): //Distance between two points distance(la1, lo1, la2, lo2) { var La1 = (la1 * Math.PI) / 180.0 var La2 = (la2 * Math.PI) / 180.0 var La3 = La1 – La2 var Lb3 = (lo1 * Math.PI) / 180.0 – […]

  • Python testing framework: pytest and unittest comparison


    Both pytest and unittest can be written automatically. Unittest is relatively basic and convenient for secondary development and integration platform. Compared with unittest, pytest has simpler code and can use more plug-ins. Pytest can be compatible with unittest cases, but unittest cannot be compatible with pytest cases. What is the difference between them in use? […]

  • JVM Tri Color marking and read write barrier


    Trichromatic marking The main purpose of GC garbage collector is to realize memory recycling. There are two main steps in this process: memory marking and memory recycling. Introduction to tricolor marking method Three color marking method is mainly used to mark memory blocks that can be recycled efficiently. image.png Tri Color marking is used as […]

  • 「Golang」sync. Once usage and source code explanation


    preface In our development process, we often use the classic design pattern of singleton mode. Singleton mode can help developers perform initialization or function call operations only once during program operation for a certain variable or object or function (method), such as initialization for a certain type of connection pool (such as database connection pool) […]

  • JSP from simple to deep (12) — form editing


    For example, the logo library from the blazix server cannot be used in your system environment, so how about not using the logo library to achieve similar functions? This tutorial is designed for this problem. This problem can be solved, but the code should be longer. Basically, you have to edit the HTML flag yourself […]

  • JSP from simple to deep (11) — tag library


    JSP 1.1 proposes a method of extending JSP flags, which is named “flag library”. These libraries allow additional flags like jsp:include or jsp:forward, but they are not prefixed with jsp: and they also attach some features. To introduce the logo library, we use the blazix logo library as an example in this tutorial. This logo […]

  • JSP from simple to deep (8) — JSP Tags


    Another important syntax for JSP is tags. JSP tags does not use <%, but only the < character. JSP tag is a bit like HTML tag. JSP tags can have a “start tag”, a “tag body” and an “end tag”. Both the start and end signs can use the name of the sign, which is […]

  • Intrigue with rust · it’s time to mark the life cycle


    Rskynet is just a small project with more than 300 lines of code… Or an extremely small project. Its function is to read the off file recording polyhedral information, calculate the polyhedral bounding sphere, semi automatically generate the model and view files in POV ray scene based on the center of the bounding sphere, and […]