2020-08-28 Source of topic: http://www.h-camel.com/index.html
[html] What are the ways of cross-domain communication?
JSONP
Ajax
WebSocket
CORS
Hash
postMessage
Technical introduction https://www.cnblogs.com/qianguyihao/p/8523576.html
[css] Tell me about the detailed process of CSS assignment of element attributes?
In-depth CSS attribute assignment
https://blog.csdn.net/weixin_33712881/article/details/87977330
[js] What is the difference between undefined and not defined in js?
The meaning of not defined is that it is not defined, console.log(xl); will prompt the reference error of referenceError, the variable has not been defined, even the declaration.
The meaning of undefined is undefined, var xl; console.log(xl); will prompt undefined, there is no exception, you can continue to run. Explain that the variable has been declared, but not defined.
[Soft skills] Tell me about your understanding of continuous integration, what problems does it solve and how to use it in the front end?
Continuous integration, frequently integrates code into the backbone, builds, compiles and tests in an automated manner through the continuous integration process, and provides unit packages that can be deployed and released.
The purpose is to quickly iterate the product while maintaining the high quality of the code
The core measure is that the code must pass automated testing before it is integrated into the backbone. As long as one test case fails, it cannot be integrated.
General practice of continuous integration: pull code through svn or other tools -> automated build -> automated compilation -> automated testing -> automated deployment -> automated publishing -> email notification
Value lies in
1. Reduce risks. Because continuous integration continues to build, compile and test, problems can be found very early, so the cost of repair is less;
2. Continuously check the system health to reduce problems caused by release risks;
3. Reduce repetitive work;
4. Continuous deployment, providing deployable unit packages;
5. Continuous delivery of available versions;
6. Enhance team confidence;
Reposted from https://www.cnblogs.com/wysk/p/7517277.html