SEARCH KEYWORD -- abstract interface


  What is the use of empty struct in GoLang

In Go, an empty struct struct{} is a struct with no fields that may appear to be of little use, but in reality, it can be useful in certain situations and become a simple and efficient solution in code. As a semaphore or lock Because the empty struct has no fields, it can be conveniently used to implement some concurrency control functions, such as mutex locks, read-write locks. We can use chan struct{} to implement an unbuffered channel for controlling concurrent access. package main import ( ...

   GOLANG,EMPTY STRUCT     2024-04-05 23:54:03

  Understanding GoLang interface

If goroutine and channel are considered as the foundation for GoLang concurrency, interface would be the key for data types in GoLang. In practical Go programming, almost all data types are built/used around interfaces, interface is the core of GoLang data structures. Go is not a typical OOP language, it has no class and inheritance concept syntactically. But it doesn't mean that there cannot be polymorphism in GoLang. Because of interface, it achieves the same polymorphism effect as in C++, tho...

   INTERFACE,GOLANG     2021-05-15 04:16:42

  Configure static IP for Linux

When a Linux server is running, it has to have an IP so that other machines can talk to it. It is often desired that the server would own a static IP so that every time other machines want to connect to it, the same IP address would be used. This is extremely useful when there are virtual machines installed on a host machine where the virtual machine would start and stop now and then.  To configure static IP address for a Linux server, the /etc/network/interfaces needs to be updated. Assumi...

   LINUX,NETWORK,STATIC IP,DNS     2017-07-08 08:39:58

  Google upgrades its built in calculator

Google search engine is more and more intelligent.It has been a long time since Google integrated a built in calculator in its search engine. Today, Google upgraded its built in calculator function in its search engine, a new calculator interface with 34 buttons is added.Before upgrading, if you type 6+7 in the search field, Google will only show the answer 13. But now, if you enter this formula again, in addition to the answer, it will display one calculator interface with 34 buttons. See follo...

   Google,built in,Calculator,Upgrade     2012-07-25 11:07:33

  Art of code comment

Note : This post is just for fun. Please be careful about these tricks. Code comment is to provide complementary comment to abstract codes. We will introduce two comment styles while we are debugging our codes. we should avoid these styles in production codes. 1. if else style Only execute eatKfc() //* eatKfc(); /*/ eatMcdonalds(); //*/ Only execute eatMcdonalds() /* eatKfc(); /*/ eatMcdonalds(); //*/ Execute both //* eatKfc(); //*/ eatMcdonalds(...

   Comment,Style     2013-08-19 04:19:40

  How does PHP session work?

This article is about how PHP session works internally. Below are the steps : 1. Session in PHP is loaded into PHP core as an extension, we can understand it as an extension. When session extension is loaded, PHP will call core functions to get the session save_handler, i.e interface or functions for reading and writing session data. By default, PHP will handle session data by writing and reading files on the server. But PHP also supplies custom methods for handling session data, we can use sess...

   PHP, session, mechanism     2012-12-28 13:36:49

  Binary tree iterator algorithm

Binary tree pre-order,in-order and post-order traversal are basics in algorithm and data structure.And the recursive binary tree traversal is a classical application of recursion. We define a binary tree node as : // C++ struct Node { int value; Node *left; Node *right; } In order binary tree traversal can be: // C++ void inorder_traverse(Node *node) { if (NULL != node->left) { inorder_traverse(node->left); } do_something(node); if (NULL != node->righ...

   Binary tree,Iterator,Traversal     2013-07-14 21:51:09

  this keyword in Lambda expression in Java 8

Since the release of Java 8, people are excited to see a big feature added to this language which is existing in other languages for a long time -- Lambda expression. The introduction of lambda expression in Java 8 gives people an easy way or a vertical to horizontal way to solve problems. There are many posts on the Internet which shows how to use lambda expression in Java, such as Lambda Quick Start and Java 8 Lambda Expressions Tutorial with Examples. In this post, we will only focus on the t...

   THIS,LAMBDA EXPRESSION,JAVA 8     2014-06-01 03:57:05

  Polymorphism in OOP Programming

Polymorphism is the capability of an action or method to do different things based on the object that it is acting upon. This is the third basic principle of object oriented programming. Overloading, overriding and dynamic method binding are three types of polymorphism. Overloaded methods are methods with the same name signature but either a different number of parameters or different types in the parameter list. For example 'spinning' a num...

   JAVA,OOP,POLYMORPHISM,OVERLOADING,OVERRI     2014-10-23 08:11:50

  JSON unmarshal in GoLang

In almost all mainstream programming languages, there is either built-in or third-party library to support parse JSON data because it is so popular for organizing and transferring data among different services. In GoLang, the built in json package also provides functions for marshalling and unmarshalling JSON data. Marshalling GoLang struct to a JSON string is relatively simple, just need to call json.Marshal(), it's a bit complicated to unmarshal an arbitrary JSON string into a GoLang struct ob...

   GOLANG,JSON,UNMARSHAL,EMPTY INTERFACE     2019-11-09 21:57:30

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