• On react


    installreactScaffolding //Mode 1 yarn global add create-react-app create-react-app react-test //Mode 2 npx create-react-app react-test reactResponsible for logic control reactDomResponsible for rendering After saving the code, the code is formatted?? JSXWhat is it? It looks likejsandhtmlA mixture ofJSX, the actual core logic isjsrealization Basic grammar // App.js import React from ‘react’; import logo from ‘./logo.svg’; import […]

  • Canvas realizes drawing, zooming, moving and saving historical state of pictures, pure dry goods (with conversion formula attached)


    Original link: https://juejin.im/post/5e7173… Hahaha, I’m here again. This time, I’ll bring you some articles about canvas functions. I hope you like them! This CSS3 variation formula can be applied to the commontransformAttribute or mobile terminal, we can zoom map and so on! preface Because I am a junior, I am looking for an internship recently. […]

  • From getting started to using Redux


    Welcome to the official account: n square.If you have any questions or suggestions, please leave a message in the background. I will try my best to solve your problems. brief introduction Redux is a predictable state container for JavaScript applications. It’s easy to understand observer patterns that are familiar with design patterns. It is the […]

  • What does zookeeper do in Kafka?


    Zookeeper is an integral part of Kafka, which shows its importance. Therefore, it is necessary for us to understand the specific work of zookeeper in Kafka. Moreover, this is often asked during interviews. Zookeeper stores some information about consumer and broker, so it explains the function of zookeeper from these two aspects. 1. broker state […]

  • Step by step to teach you to implement the full version of promise / A + specification


    preface Hello, guys. I’m going to take you to write promise. As a front-end developer, in daily work, one of the problems is asynchronous programming So what is asynchronous programming? Getting data from the server is called asynchronous programming stay node.js To read the file, this process is also asynchronous There are currently four solutions […]

  • LSTM (short term memory network)


    In the last paper, we summarize RNN model. Because RNN also has the problem of gradient disappearance, so it is difficult to deal with long series of data. The big bulls have improved RNN and obtained the special case LSTM (long short term memory) of RNN. It can avoid the gradient disappearance of conventional RNN, […]

  • Tencent one side


    What are the layers of network protocol Physical layer: the task of the physical layer is to transparently transmit bitstreams Data link layer: the main task is to be responsible for error free transmission of frame based data on the line between two adjacent nodes Network layer: the main task of the network layer is […]

  • Practice sharing of using rxjs to manage the state of react application


    With the increasing complexity of front-end applications, how to manage the application data has become an unavoidable problem. When you’re facingBusiness scenarios are complex, requirements change frequently, and various application data are interrelated and dependentHow do you manage the application’s state data when it comes to large-scale front-end applications? We think that the applied data […]

  • Implementing a vuex plug-in from scratch


    1、 Review the use of the official vuex plug-in To implement a vuex plug-in yourself, you mustLet’s first understand the basic use of the vuex plug-inWhen we use vuex, we usually define a store.js The following are the main tasks in the document: ① Introducing the vuex module; import Vuex from ‘vuex’; ② Introducing Vue […]

  • Promise from two blind eyes to binocular light (3) – several key problems of promise (1)


    How to change promise status How to change the state of promise? Project maintains three internal states, namely, pending, rolled (officially called fully) and rejected, When resolve (value) is executed, the status changes from pending to resolved When a reject (reason) is executed or an error is thrown, the status changes from pending to rejected […]

  • Tips for using [curl] curl command


    Curl is the most commonly used website troubleshooting method. Enter curl — help on the terminal to see the details of the command parameters of curl. -L parameter Only the header information is returned, and the request result is as follows: curl -I www.baidu.com When monitoring the web service, we can judge whether the web […]

  • HPB wallet and middleware interface


    In order to make it easier for developers to develop or use HPB wallets, HPB wallets developers have prepared a common API interface introduction. 1、 HPB version controller 1. Query version No describe: apply wallet to query version number. Request description: Request method: Post Request URL: :9888/HpbComponent/cms/version Call example: [ “1”,”0″ ] Request parameter […]