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How to write javascript at the beginning

PHPz

Release： 2023-04-25 09:56:25

Original

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JavaScript is a programming language widely used in web development, adding interactivity and dynamic features to websites and web applications. Before writing JavaScript code, there are some rules to follow at the beginning.

Introduce JavaScript script

Before embedding JavaScript code in an HTML file, you need to introduce JavaScript script. You can use the <script> tag to put the JavaScript file path or internal code in it. For example:

<!DOCTYPE html>
<html>
   <head>
      <script src="path/to/your/script.js"></script>
   </head>
   <body>
      ...
   </body>
</html>

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This allows you to introduce external JavaScript scripts into HTML files.

Start writing JavaScript code

After introducing the external JavaScript script, you can start writing JavaScript code. JavaScript code should be placed in the <script> tag, for example:

<!DOCTYPE html>
<html>
   <head>
      <script src="path/to/your/script.js"></script>
      <script>
         // your JavaScript code here
         console.log('Hello, World!');
      </script>
   </head>
   <body>
      ...
   </body>
</html>

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In the above code, the console.log() function will be in the browser console Output information.

Use strict mode

When writing JavaScript code, it is recommended to enable strict mode. Strict mode reduces the likelihood of errors and makes your code more secure. You can add the 'use strict'; statement at the top of the code, for example:

'use strict';

// your JavaScript code here
let value = 10;
console.log(value);

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to enable strict mode in the code.

Add comments

When writing JavaScript code, it is very important to add comments. Comments can help other developers understand your code, and they can also help you read and maintain your own code in the future. You can use // or /* */, for example:

// this is a single-line comment
let value = 10;

/*
this is a
multi-line
comment
*/
console.log(value);

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In the above code, the comments explain the code.

Summary

When you start writing JavaScript code, you need to introduce JavaScript scripts and start writing code. It is recommended to add strict mode and comments to improve code quality and readability. The above are several ways to write JavaScript at the beginning, which can be selected and used according to needs.

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