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This article mainly explains "analyzing the difficult knowledge points of css and javascript". The content of the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn "analyze the difficult knowledge points of css and javascript".

JavaScript is a scripting language belonging to the network, which has been widely used in Web application development. It is often used to add a variety of dynamic functions to web pages and provide users with a more smooth and beautiful browsing effect. Usually JavaScript scripts implement their own functions by embedding them in HTML.

CSS (Cascading Style Sheet) cascading style sheet

Presentation (presentation)-Design the presentation style of a web page, that is, "how to display relevant content"

CSS is a markup language that separates style information from web content, and we use css to define styles for each element; it is mainly used to beautify HTML pages.

The syntax is: selector {property:value} (selector {attribute: value}).

By setting the corresponding style properties, you can modify the display and location of the elements in the html document, such as color, font, font size, width and height, position, background, etc.

JS (JavaScript) is a dynamic scripting language

Behavior-controls the behavior (effect) of a web page, that is, "how the content should react to events"

The use of JavaScript code can make the foreground interactive (click events), which is often used to add a variety of dynamic functions to the web page to provide users with a more smooth and beautiful browsing effect. Usually JavaScript scripts implement their own functions by embedding them in HTML.

Common features of JavaScript:

1. Embed dynamic text into HTML pages

2. Respond to browser events

3. Read and write HTML elements

4. Verify the data before it is submitted to the server

5. Detect the browser information of visitors

6. Control cookies, including creation and modification

HTML page loading and parsing process:

The user enters the URL (assuming it is a html page and is visited for the first time), the browser makes a request to the server, and the server returns the html file.

The browser starts loading the html code and finds that there is a tag inside the tag that refers to the external CSS file.

The browser sends a request for the CSS file, and the server returns the CSS file.

The browser continues to load some of the code in html, and the CSS file is in hand, so you can start rendering the page.

The server returns the image file, because the picture occupies a certain area, which affects the layout of the following paragraphs, so the browser needs to go back and re-render this part of the code.

The browser finds a tag that contains a line of Javascript code and run it quickly.

The Javascript script executes this statement, which commands the browser to hide one of the code (style.display= "none"). The browser has to re-render this part of the code.

Finally, it was executed.

When the user clicks the "skin change" button in the interface, Javascript asks the browser to change the CSS path of the < link > tag.

The browser requests a new CSS file from the server to re-render the page.

Thank you for your reading, the above is the content of "analyzing the difficult knowledge points of css and javascript". After the study of this article, I believe you have a deeper understanding of the problem of analyzing the difficult knowledge points of css and javascript, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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