• Java basic syntax (summary)


    Keywords & identifiers The concept and characteristics of key words Concept: Java keywords are predefinedFor JavaCompilers have special meanings. They are used to represent a data type, or the structure of a program,Keywords cannot be used as variable names, method names, class names, package names, and parameters. features: Full lowercase Special colors in enhanced Notepad […]

  • Java Basics


    1: Identifier, keyword, data type, variable, constant. 2: Operators and expressions 3: Selection cycle structure of process control 4: Array        identifier : used to define constants, variables, methods, classes, interfaces, which are composed of letters, numbers, underscores and dollar characters.        keyword: for example, abstract, class, final, etc The data […]

  • Go microservices of clean architecture: coding style


    Coding style is a relatively boring topic in programming, but a proper coding style is essential for an effective programmer. It has three components: Application Layout Coding rules or styles Naming convention I have discussed the program structure in the go microservices of clean architecture: program structure ¹, so this article will cover the latter […]

  • B-trees


    Most MySQL indexes (PRIMARY KEY, UNIQUE, INDEX, and FULLTEXT) are stored in B-trees. Exceptions: Indexes on spatial data types use R-trees; MEMORY tables also support hash indexes; InnoDB uses inverted lists for FULLTEXT indexes B-Tree A tree data structure that is popular for use in database indexes. The structure is kept sorted at all times, enabling fast lookup for exact matches (equals operator) and ranges (for […]

  • The use and attention of const


    Const is used to define constants and cannot be modified after definition. It is suggested that const should be used first in development, which can effectively avoid the problem of variables being modified by other colleagues. Must be assigned when const is defined. Const name; // this is not allowed. An error will be reported […]

  • An example of using regular expression to reconstruct code and remove redundant code


    Before refact: lots of duplicate code After refact: eliminate duplicate code with map. In the current branch, VAR usregx = / XXXX /. In fact, a regular expression object is defined by literal quantity, which costs more than defining a string. In fact, it is not necessary to define the map every time. You can […]

  • Dried food! Some suggestions on Java code performance optimization


    A steed can’t leap in ten steps, but a horse can’t do ten things. Improve the quality of code, optimize performance, the key is to adhere to! If you work hard to eliminate the “bad taste” of code and persist in accumulation, you can not only improve your coding level, but also make the code […]

  • C notes 03 constant & storage class


    constant Constants are fixed values that do not change during program execution. These fixed values are also calledLiteral。 Constants can be any basic data type, such as integer constants, floating-point constants, character constants, or string literals, as well as enumeration constants. integer constant Integer constants can be decimal, octal, or hexadecimal. Prefix specifies the cardinality: […]

  • Tensorflow 2 quick tutorial, a must for beginners


    About tensorflow 2 Tensorflow is a deep learning open source tool released by Google in November 2015. We can use it to quickly build deep neural networks and train deep learning models. The main purpose of using tensorflow and other open source frameworks is to provide us with a module toolbox that is more conducive […]

  • ES6: difference between export default and export


    Difference between export default and export: 1. Export and export default can be used to export constants, functions, files, modules, etc2. You can import it in other files or modules by using the name of import + (constant function | file | module), so that it can be used3. In a file or module, there […]

  • Deep understanding of Java virtual machine – thorough analysis of JAVA memory area


    This article mainly introduces JAVA memory area, which is also some of the most basic knowledge of Java virtual machine. After understanding these knowledge, you can better perform JVM tuning or more in-depth learning. Originally, these knowledge is obscure, so I hope to be able to explain it thoroughly and vividly. 0 runtime data area […]

  • Definition and use of global scope constants, fields, properties and methods in C


    scene In development, there are often some global scope constants, fields, properties, methods, etc. These need to be set to global scope save and have unique instances. Note: Blog home page:https://blog.csdn.net/badao_liumang_qizhi Official accountDomineering procedural apeGet programming related ebooks, tutorials and free downloads. Realization First, create a global class. The name is optional. This is global. […]