How to do outreach in javascript

JavaScript is the most commonly used scripting language in the field of web design. In web pages, if you want to use JavaScript, there are generally two ways - inline and outbound. This article will mainly introduce how JavaScript is used for outreach.

What is external linking

Simply put, external linking is a method of referencing external JavaScript files in web pages. In an HTML document, you can use the tag to reference an external JavaScript file. When referencing external JavaScript files, unlike the inline method, the code is not embedded in the HTML file. Its advantages are as follows:

Easy to maintain: Separate the JavaScript code from the HTML document. When modifying the code, you only need to modify a separate file, which facilitates maintenance and management. Reduce page code size: If you write a piece of JavaScript code in every Web page, it may cause the page size to be too large and affect the performance of the website. Outreach can reduce the amount of page code and improve the response speed of the website. The code format for introducing external JavaScript files is as follows:

Among them, the type attribute indicates the script language type, and the src attribute points to the external JavaScript file path. Next, we will use a simple example to illustrate how to externally link JavaScript files in HTML files.

Example

Suppose we want to reference an external JavaScript file in an HTML file. The file name is "external.js" and the directory is in the "js" directory. The steps are as follows:

Create an HTML file named "external.html". The code in the file is as follows:

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In the above code, we define a button click event and call a function named "myFunction()". At the end of the HTML code, we introduce the "js/external.js" file through the tag.

Create a JavaScript file named "external.js". The content is as follows: function myFunction() { alert("Hello World!"); } external.js file defines a function myFunction(), which The function pops up a message box, "Hello World!".

At this point, save the two files in the same folder, then open the "external.html" file, you will see a page with a button, click the button, and a dialog box will pop up showing "Hello World!" message. It means that the method of introducing external js files has been successful.

Notes

The function names and variable names specified in the external js file can be referenced in the HTML file. If two or more functions with the same name are defined in an external js file, function coverage or function failure may occur. It is recommended to follow naming conventions when naming, name different functions or give functions different aliases. When introducing external JavaScript files, the introduced JavaScript code needs to be in the same domain as the file where the HTML document page is located. Otherwise, cross-domain issues will occur. Summary:

External JavaScript can improve the maintainability of the code, reduce the amount of page code, and improve the response speed of the website. In application, pay attention to things to avoid errors.