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Can JavaScript run alone?
- 青灯夜游Original
- 2022-09-29 17:48:403899browse
JavaScript cannot be run alone. JavaScript is a scripting language that cannot be run independently like an exe program and can only be executed in the host environment. Two running methods: 1. Use the script tag to put the JavaScript code in HTML and run it with the help of the browser environment; 2. Run the JavaScript code with the help of the node.js environment.
The operating environment of this tutorial: windows7 system, javascript version 1.8.5, Dell G3 computer.
JavaScript is a cross-platform interpreted, dynamically typed, weakly typed, prototype-based scripting language. It cannot be run independently like an exe program and can only be executed in the host environment.
Running method 1: You need to use the script tag to put it in HTML and run it with the help of the browser environment.
Embedding JavaScript scripts in HTML pages requires the use of the <script> tag. Users can directly write JavaScript code in the <script> tag</script>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>JavaScript程序</title>
<script type="text/javascript">
document.write("<h1>PHP中文网：https://www.php.cn/</h1>");
</script>
</head>
<body></body>
</html>
You can also put JavaScript code in a JavaScript script file. JavaScript script files are text files with the extension .js and can be edited using any text editor. JavaScript files can then be imported into HTML pages using the <script> tag. </script>
Example:
Write the following JavaScript code in the test.js file.
alert("PHP中文网：https://www.php.cn/");Insert a <script> tag within the <head> tag of the HTML document. Define the src attribute and set the attribute value to a URL string pointing to an external JavaScript file. The code is as follows: <br/></script>
<script type="text/javascript" src="test.js"></script>
Note: When using the <script> tag to include external JavaScript files, the default file type is Javascript. Therefore, regardless of whether the loaded file has a .js extension or not, the browser will parse it as a JavaScript script. </script>
Running method 2: You can run it with the help of node.js.
1. Create and write a JavaScript script file
2. Open the cmd command window
3. Directly execute the "node js file name specific path" command to execute the js script file
My js file is in the D:\nodejs\demo directory, so execute
node D:\nodejs\demo\hello.js
4. Or, first use the "cd directory path" command to locate the directory where the js file is located, and then execute: node fileName command ( fileName file name), you can execute the corresponding js script file. Example:
node hello.js
Description:
For the js file following node, .jsThe suffix can be added or not
Note:
It is best not to use node.js and Chinese in the file name, and there should be no spaces in the file name
More node related knowledge , please visit: nodejs tutorial!
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