Programmer Group

ES7 has two more features than ES6 1.Array.prototype.includes 2. Exponent operator ES8 new proposal: 1.Object.values / Object.entries 2. String padding 3.Object.getOwnPropertyDescriptors 4. Trailing commas in function parameter list and call 5. Asynchronous functions Detailed explanation: 1.A ...

  This chapter talks about the routing of angular Let's talk about how to introduce angular routing. In the beginning, the new angular project has its routing configured for you, but it depends on app.module.ts 1. First, the routing module should be introduced at the top import {RouterModule, Routes} from '@angular/ro ...

This article casually wrote about my own understanding of websocket communication protocol, Demo played on two frameworks, and then stepped on several pits and unfilled pits (welcome to comment and guide).   What is WebSocket? Why use WebSocket? WebSocket is a kind of network communication protocol. When it comes to network communication protoc ...

Custom verifier Basic syntax: xxx(params:AbstractControl):{[key:string]}:any{ renturn null; } The type of the incoming parameter is AbstractControl, which is the common parent class of FormGroup, FormControl and FormArray. The incoming parameter declares what object type the validator is used for (the three mentioned above) The return v ...

order Before learning service, we should understand what the "service" is used for. In fact, this service is just like the "service" in real life, such as: hairdressing service, foot washing service So what are the services of AngularJS? In AngularJS, a service is a function or object that can be used in yo ...

First, briefly explain the role of lazy loading: As the name implies, laziness means that resources that need to be loaded are not loaded the first time, but are loaded when the page needs to be used, usually to improve the efficiency of loading the first page. Here is a simple example of the basic use of lazy loading ...

html code: When the input departs from the change event, the touchUpdateImg method will be called. The file object will be passed in and the imgsmall property will be displayed. The file object will be read through the FileReader object. I used apply to monitor. I didn't use apply to monitor before. When I didn't use ...

We often use paging to display data when we do projects. The principle is very simple: each time we click (next / last) a page, we send a request to the background to obtain relevant JSON data. What I'm demonstrating here is that every time I request, I will pass two parameters (pageSize – data to be displayed on ...

The processing of Android return key in ionic 3 learning About provider Understand the provider of ionic3 provider is a concept defined by ionic itself, similar to our service on angular. There are some similarities and differences between the two. Contrast: Difference technology Commands used file name Route ...

5.vins_estimator Basically, most of the functions in VINS are under this package, including IMU data processing (front end), initialization (I think it may belong to front end), sliding window (back end), nonlinear optimization (back end), key frame selection (part of content) (front end). When I firs ...