Why did you write this blog post? Some time ago, I chatted with a small friend of the headline asking what questions the front end of the interview would ask. He said that if it was his interview, event-loop would definitely ask. I talked a lot that day, and event-loop left a deep impression on ..
Category : javascript
React16.3.0 started with some changes in the life cycle. This article mainly introduces the life cycle after React16.3.0. Life cycle before React16.3.0: I believe everyone is already familiar with the life cycle of react components before version 16. Version 16 react has made some modifications to the life cycle function of the component, which will ..
Promise is a high-frequency question in front-end interviews. When I was an interviewer, the probability of asking Promise exceeded 90%. As far as I know, most companies would ask some questions about Promise. If you can write standard source code according to the standard of PromiseA+, then I think you can give perfect answers to ..
Implementation Principle of Pull-down Refresh Implementation of pull-down refresh is mainly divided into three steps: Monitor the native touchstart event and record the value of its initial position, e.touches [0]. pagey; Monitor the native touchmove event, record and calculate the difference between the current sliding position value and the initial position value. when the difference ..
Webpack core concepts: Entry: entrance Module: module, everything in the webpack is a module. Chunk: code base, a chunk is composed of more than ten modules, used for code merging and splitting. Loader: module converter, which is used to convert the original content of the module into new content according to requirements Plugin: extension plug-in, ..
It is difficult to debug the mobile terminal. Most of the time, when we are developing the mobile terminal, we use the mobile phone simulator to debug it on the PC terminal first. We will test it on the browser of the mobile terminal only after there is no problem. At this time, if there ..
This keyword is one of the most complicated mechanisms in JavaScript. It is a special keyword that is automatically defined in the scope of all functions. However, I believe many JsvaScript developers are not very clear about what it refers to. I heard that you know this very well, is it true? Please answer the ..
In the cold winter of the Internet, major companies have reduced HC and even adopted “layoff” measures. Under such a big environment, it is necessary to make more efforts to get a better job. A year ago, perhaps you could get approval by figuring out closure, this, prototype chain. But now, obviously not. This article ..
In the cold winter of the Internet, major companies have reduced HC and even adopted “layoff” measures. Under such a big environment, it is necessary to make more efforts to get a better job. A year ago, perhaps you could get approval by figuring out closure, this, prototype chain. But now, obviously not. This article ..
With the development of the Internet, various Web applications have become more and more complex, meeting various needs of users. At the same time, various network security problems have followed. As front-end engineers, we can’t escape from this problem either. Today, let’s take a look at what security problems exist in the Web front-end and ..
To know what it is and why it is, first understand three concepts: 1. What is synchronization? Synchronization means that when a “call” is issued, the “call” will not return until the result is obtained. But once the call returns, you get the return value. In other words, it is the “caller” who actively waits ..
About [Step-By-Step] If you don’t take too many steps, you’ll reach a thousand miles. Step-By-Step(Click to enter the project) It was me at2019-05-20The beginning of a project, the project vision: one step at a time, quantitative change leads to qualitative change. Step-By-StepOnly face-to-face questions will be issued on weekdays, mainly considering that some of the ..