JDK1.8 new feature: still writing null pointer check code repeatedly? Use Optional now
1. Foreword
As a Java programmer, whether a novice or a veteran expert, he must have encountered all kinds of abnormal errors. In a foreign article, the ranking list of exception types is counted, as shown in the following figure:
Yes, you're right. NullPointerException tops the list.
Charles Antony Richard Hoare, the inventor of Null Referen ...
Posted by habs20 on Sat, 21 May 2022 10:20:38 +0300
vue2 knowledge points: list rendering (including: v-for, key, value range, list filtering, list sorting, data change principle of vue monitoring object or array, and summarizing vue data monitoring)
1, v-for
<li v-for="item in items">{{item.name}}</li>
List rendering
v-for
A set of values can be rendered in a list. The syntax form is: item in items，
items Is an array of source data and item Is an alias for an array element iteration.
stay v-for Block, full access to the parent scope attr ...
Posted by Walle on Sat, 21 May 2022 04:06:19 +0300
VUE conditional rendering
catalogue
1. v-if
1.1 template
1.2 v-else
1.3 v-else-if
1.4 manage reusable elements with key
2.v-show
3.v-if vs v-show
4. Use V-IF with v-show
1. v-if
The v-if instruction is used to render a piece of content conditionally. This content will only be rendered when the expression of the instruction returns the truth value.
< ...
Posted by PerfecTiion on Fri, 20 May 2022 01:08:21 +0300
Vue filter, custom key modifier, custom instruction, life cycle knowledge point
1. Filter
1. Define syntax
The first parameter in function is fixed. It is always the parameter passed in front of the filter pipeline symbol
//The first parameter in function is fixed. It is always the parameter passed in front of the filter pipeline symbol
Vue.filter("msgmat", function(msg) {
return msg.replace("beauty", "Fairy ...
Posted by beanman1 on Thu, 19 May 2022 18:26:14 +0300
Vue Basics: template syntax
1. Template syntax
1.1 overview of template syntax
Vue.js uses an HTML based template syntax that allows developers to declaratively bind the DOM to the data of the underlying Vue instance. All Vue JS templates are legal HTML, so they can be parsed by standard browsers and HTML parsers.
In the underlying implementation, Vue compiles the templat ...
Posted by imagenesis on Thu, 19 May 2022 06:55:08 +0300
From vue to elementUI project
Detailed explanation of common components of Element
install element
Go to the folder and execute the following command to install
yarn add element-ui -S // -S indicates the dependencies used by both the production environment and the development environment
Introduce element in main.js, you can use it in the page
import Vue from 'vue'
impor ...
Posted by Birdmansplace on Wed, 18 May 2022 08:39:48 +0300
be based on. NetCore development blog project StarBlog - start building a Web project
Series articles
be based on. NetCore development blog project StarBlog - (1) why do you need to write your own blog?be based on. NetCore development blog project StarBlog - (2) environment preparation and creation projectbe based on. NetCore development blog project StarBlog - (3) model designbe based on. NetCore development blog project St ...
Posted by Z3RO21 on Tue, 17 May 2022 22:18:39 +0300
Surprise! VUE data can't drive the view?
Vue cannot detect the addition or deletion of object properties
1. Emphasis: Vue cannot detect the addition or deletion of object attributes
Official website - deep response principle( https://cn.vuejs.org/v2/guide ...) It is introduced in: due to the limitations of modern JavaScript (and the abandonment of Object.observe), Vue cannot detect ...
Posted by dannyone on Tue, 17 May 2022 17:49:59 +0300
2020-9-14, react framework entry, scaffold, component and event binding
Content: introduction to react framework, scaffolding, components, event binding Date: September 14, 2020
1, Introduction to react framework
1. Introduction
react is an Open-Source Library of facebook and a JavaScript library for building user interfaces. It is not a complete MVC. It can be considered as the V (view layer) in MVC at most. ...
Posted by amalosoul on Tue, 17 May 2022 16:30:47 +0300
What is Spa (single page Web application)? And Vue routing
single page web application (SPA)
An application with only one Web page is a Web application that loads a single HTML page and dynamically updates the page when the user interacts with the application.
Compare traditional applications
Single page application: Only the first time will the page be loaded, and each subsequent request is only ...
Posted by Mobile on Mon, 16 May 2022 20:42:07 +0300