JavaScript 自动分号插入（JavaScript synat:auto semicolon insertion）

网络编程 2024/11/13 佚名

3 2 1

看代码：
HTML：
复制代码代码如下:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>index</title>
<link rel="stylesheet" href="resources/css/ext-all.css" />
<script type="text/javascript" src="/UploadFiles/2021-04-02/ext-base.js"><script type="text/javascript" src="/UploadFiles/2021-04-02/ext-all.js"><script type="text/javascript" src="/UploadFiles/2021-04-02/index.js"><script type="text/javascript">
Ext.onReady(myNameSpace.app.init, myNameSpace.app);
</script>
</head>
<body>
<div id="mydiv"></div>
<p id="1">1</p>
<p id="2">2</p>
<p id="3">3</p>
<p id="4">4</p>
</body>
</html>

index.js内容：
复制代码代码如下:
/*
Author:binarytree
*/
// 填充图片的本地引用
Ext.BLANK_IMAGE_URL = 'resources/images/default/s.gif';
// 命名空间
Ext.namespace('myNameSpace');
// 创建应用程序
myNameSpace.app = function()
{
return
{
init: function()
{
alert('程序初始化完毕');
}
};
}();

网上索引一番，等到如下结果：ECMAScript规定在有些情况下，可以对JavaScript语句执行自动分号补全，return就是其中之一；
Certain ECMAScript statements (empty statement, variable statement, expression statement, do-while statement, continue statement, break statement, return statement, and throw statement) must be terminated with semicolons. Such semicolons may always appear explicitly in the source text. For convenience, however, such semicolons may be omitted from the source text in certain situations. These situations are described by saying that semicolons are automatically inserted into the source code token stream in those situations.
我index.js里的第11行处，在JavaScript解析引擎解析的时候自动补全了分号，导致后面的语句不能执行；

解决办法：return后面的大括号不要在新行起用，避免被自动补全分号；
虽然很简单,但对我是今天的新知之一；^__^

JavaScript,自动分号插入