Where to put javascript

Where is JavaScript placed?

JavaScript is a programming language used for web front-end development, which can make web pages more dynamic and interactive. So, where do we put JavaScript?

1. Internal script

In HTML documents, we can embed JavaScript code snippets in the

or tags. This is the most common way for developers to write JavaScript code directly in HTML files. However, this will cause the HTML document to become bloated, which is not conducive to code management and maintenance.

2. External script

External script is a method of placing JavaScript code in a separate JS file, using the <script> tag to link the JS file to HTML document. This approach can make the code more concise, easier to maintain and manage, and can share JavaScript code among multiple HTML pages. </script>

3. Event handling function

Event handling function is a way to associate JavaScript code with HTML events. Developers can use the addEventListener() method or declare events directly in HTML tags to bind JavaScript functions. This method is suitable for small projects without a lot of JavaScript code.

4. Inline event handling

If we only need to execute some simple JavaScript code directly on a specific HTML element, we can use inline event handling. This approach is suitable for simple projects or when you need to use JavaScript on a small number of HTML elements. However, this approach will make the HTML document confusing and is not conducive to code maintenance.

No matter which way you place the JavaScript code, you should pay attention to the following points:

1. For large projects, you should follow the single responsibility principle as much as possible and split the JavaScript code into multiple files for easy management and maintenance.
2. JavaScript code should use compression and obfuscation techniques to improve loading speed and protect code security.
3. External scripts should be placed at the bottom of the tag to avoid blocking the rendering and loading of the HTML page.

In short, the way JavaScript is placed should depend on the size and needs of the project. Choosing the way that suits your project can make the code easier to manage and maintain.

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