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Author: Marcin WanagoTranslate: Crazy Technology House Original: https://wanago.io/2018/09/10/... Reproduction is strictly prohibited without permission JavaScript Testing Tutorial - part 1: Unit testing with Jest JavaScript testing tutorial - part 2: Introducing Enzyme and testing React components JavaScript Testing Tutorial - part 3: Testin ...

let and const The project built by webpack directly discards VaR and directly uses let instead of var let instead of var in for loop After variable declaration, it will not change. Please use const Destructuring assignment Concept: first deconstruct and then assign, first find out the data you need from a pile of data, and then assign the dat ...

Use components: react-native-baidu-map Get Baidu map API Address: http://lbsyun.baidu.com, after the console successfully creates the application, you can see the api of the application key. install yarn add react-native-baidu-map Native part Android configuration react-native link react-native-baidu-map Configure the Android manifest.xml fi ...

It rained three times last night and kept cool all day.- Su Shi in Parrot Sky The results of the practice are published in github at: react-duce From now on, state management has become a standard for front-end projects, and we'll bring in libraries like MobX and Redux to manage the state we apply, whether it's unnecessary or not.But if we loo ...

Preface:There is a requirement for the project: jump route. Before leaving the page, you need to pop-up the box to ask whether the user is sure to leave.It is possible to use the < prompt > component of react router, but how to use the antd component (or custom component)?Please look at the following. First look at this: https://stackove ...

Let's suppose A game has three actors (A, B, c) on the stage. Each actor has an actor facing himself and forms A ring (A facing B, B facing C, C facing A). We can slap an actor in the face. No matter who slaps him, he will slap the actor he is facing (so as long as we slap anyone, they will always fan down in A ring). First, write the actors: ...

This series of tutorials teaches you how to use the Open Source js Drawing Library To create your own online drawing software.You can also look at the development tutorial for this drawing library.If you feel good, please give us a compliment and let us be more motivated to do it! This series of tutorials focuses on how to develop your own draw ...

background Form problems, whether in jQuery era or Angular/React era, are always the pain of front-end engineers, but this is impossible. There are various business requirements. For the middle and back-end business, form pages and report pages are basically the core forms of the middle and back-end business. However, React forms are really com ...

1.var,let,const ES6 recommends using let to define variables in functionsconst is used to declare a constant (values like values cannot be changed, reference type addresses cannot be changed)let and const are valid only in the last block (in curly brackets) //1.let cannot be repeated var n = 10; var n = 100; console.log(n) //100 let a=10 l ...

react Higher order functions may be a little strange to you. Let's separate higher order functions from functions and see what is higher order first and then what is component. Higher order function Can effectively reduce complexity and component volume Easy to read and understand Reduce bug opportunities In functional prog ...