Easily ignored points of js Foundation
1
if ( typeof v === 'undefined') { // true
}
if ( typeof null === 'object') { // true
}
2
Number(null) //0
5 + null //5
Number(undefined) //NaN
5 + undefined //NaN
3 integers and floating points
There are no integers at all at the bottom of JavaScript language. All numbers are decimals (64 ...
Posted by inutero on Sun, 19 Jan 2020 02:45:14 -0800
JavaScript Canvas implementation of custom polyline graph
JavaScript Canvas implementation of custom polyline graph
Hello everyone, I'm the spirit of Mengxin studio. Today, I'll tell you how to realize a good-looking custom polyline chart. According to the Convention, the implementation effect is as follows:
The picture effect is still OK. The color and cont ...
Posted by tbales on Sat, 18 Jan 2020 21:20:46 -0800
js download files, audio, video
Recently, I did a music download, downloading with tag a will jump to the url of the audio (it can't be downloaded directly on the current page). After a long time, I finally found this article:
https://www.jianshu.com/p/c31c199e1d5e Download the solution using fetch, collect a wave, thank you old m ...
Posted by eevan79 on Sat, 18 Jan 2020 19:36:33 -0800
Implementation of css+jq horizontal tree
Recently, there is a UE design that is the display of the horizontal tree. After looking up some information on the Internet, we didn't find the code of the horizontal tree. So we use:: before and:: after pseudo elements plus jq to implement it simply according to the actual needs. In the future, we have the opportunity to stri ...
Posted by mrmom on Sat, 18 Jan 2020 08:13:21 -0800
Two cases of Ajax
Case 1: verify whether the registration name is duplicate
1. Create registration page register.html
<body>
<label for="email">Your login name:</label>
<input type="text" id="username" name="username" maxlength=32/>
<input type="button" value="Verification" onclick="checkUsername();"/>
...
Posted by MentalMonkey on Sat, 18 Jan 2020 07:30:12 -0800
vue koa2 nuxt.js from scratch as front-end part of personal blog login registration function
0. Effect demonstration
It's annoying to plug in a video.You can go out and turn right to Youku. Click on me!).
1. Preparations
1.1 Front End Framework
The front end uses nuxt.js based on vue.js.Why use nuxt.js？
The first thing I did was a blog project, so SSR is important.Although it has nothing to do with the login registration described i ...
Posted by cpace1983 on Fri, 17 Jan 2020 10:56:30 -0800
Jquery Generates Barcodes to Web Pages and Prints Barcodes
background
The latest project involves generating barcodes and printing them out. Individuals often write java, but using the back end can be cumbersome.It is convenient to use js, here is a brief introduction.
There's a lot of stuff on the web about generating barcodes. JsBarcode works best with github addresses: https://git ...
Posted by hwttdz on Fri, 17 Jan 2020 08:41:04 -0800
WPS guide for browser application integration
Because the WPS plug-in uses NPAPI mechanism to interact with browsers, it is required that browsers using plug-ins must support NPAPI mechanism and enable NPAPI mechanism.
The following are common supported browsers and their versions:
FireFox browser 52 and versions less than 52 (NPAPI is no longer supported for versions higher than 52)
Chr ...
Posted by jme on Thu, 16 Jan 2020 23:02:03 -0800
android native and H5 interaction
Recently, a hybrid APP of Android native H5 was developed on the left. Before that, we haven't summarized the interaction methods between Android native and H5. Here's a summary:
1. hybrid communication is mainly the communication between the front-end JS and our Android. This is the most basic communic ...
Posted by fewtrem on Tue, 14 Jan 2020 20:32:01 -0800
tornado learning notes day06 application security
Application Security
cookie
Ordinary cookie
What do we usually have in our user list
When you are shopping, join the shopping cart and let you log in. After you log in, how does he know you are logged in
The value of token is random and exists in the cookie
Set up
Prototype: how to set cookie s
...
Posted by zulfer on Tue, 14 Jan 2020 20:27:59 -0800