Detailed explanation of three usage cases of js (with code)-JS Tutorial-php.cn

Detailed explanation of three usage cases of js (with code)

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Release： 2018-05-31 11:55:25

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This time I will bring you a detailed explanation of the three usage methods of js (with code). What are the precautions for the three usage methods of js. The following is a practical case. Let’s take a look. .

1. Inline js: js is not written separately

<!DOCTYPE html> 
<html lang="en"> 
<head> 
 <meta charset="UTF-8"> 
 <title>js使用方式1：行内js</title> 
</head> 
<body> 
<input type="button" value="点击有惊喜" onclick="javascript:alert(&#39;哈哈哈哈&#39;)"> 
<!--onclick:点击触发一个事件，alert：弹出一个对话框--> 
</body> 
</html>

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2. Internal js: the program in script can be used on the entire page

<!DOCTYPE html> 
<html lang="en"> 
<head> 
 <meta charset="UTF-8"> 
 <title>js使用方式2：内部js</title> 
 <script type="text/javascript"> 
  //声明一个函数(整个文档都可以使用) 
  function surprise() { 
   alert('恭喜你中了一百万')/*弹出框*/ 
  } 
 </script> 
</head> 
<body> 
<input type="button" value="点击有惊喜" onclick="surprise()"><!--调用函数--> 
<input type="button" value="点击" onclick="surprise()"> 
</body> 
</html>

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3. External js: Many html pages can call the set js page

<!DOCTYPE html> 
<html lang="en"> 
<head> 
 <meta charset="UTF-8"> 
 <title>js使用方式3：外部js</title> 
 <!--很多html页面都可以调用js4.js页面--> 
 <script src="../../js/js4.js" type="text/javascript" charset="utf-8"> 
 </script> 
</head> 
<body> 
<input type="button" value="点击" onclick="test()"> 
</body> 
</html>

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I believe you have mastered the method after reading the case in this article. Please come for more exciting information. Pay attention to other related articles on php Chinese website!