2020-08-16 Subject source: http://www.h-camel.com/index.html
[html] What are the different characteristics of replaceable elements and non-replaceable elements?
1. Replaceable element: Replaced element means that the label will be replaced. Including img object video textarea input, some elements can be replaced under certain circumstances, audio canvas
Professional definition: A content is not controlled by the CSS visual formatting model. The CSS rendering model does not consider the rendering of this content, and the element itself generally has an element with inherent dimensions (width, height, aspect ratio), which is called replacement element.
2. Non-replaceable elements: non-replaceable elements, then the remaining elements are non-replaceable elements.
[css] Is it safe for us to use third-party css? why?
Third-party css is not safe, and third-party pictures and third-party scripts are not safe.
<link rel = “stylesheet” href = “https://example.com/style.css” >
Third-party css scripts are closer to images than scripts, and similar to scripts, they also act on the entire page. It can do
1. Delete/add/modify page content
2. Make a request based on the content of the page
3. Respond to the interaction of many users
4. CSS cannot modify the original storage, you can build miners in CSS. (Ie, Monero miner), but malicious css can still cause a lot of damage
Transfer from: https://zhuanlan.zhihu.com/p/45148804
[js] Use js writing method to generate 4 numbers for each group of 0123456789, how many combinations and permutations there are
Analysis: 10 values, composed of 4 digits, each has 10 choices, if it can be repeated, a total of 10 * 10 * 10 * 10; if it is not repeatable, then 10 * 9 * 8 * 7 choices.
[Soft skills] For example, what are the resolutions of mainstream mobile phones?
Generally 2080*1080 or 2k resolution
Check it out here https://www.zhihu.com/question/20440405