javascript:void(0) meaning
We often use code like javascript:void(0), so what does javascript:void(0) mean in JavaScript?
The most critical thing in javascript:void(0) is the void keyword. void is a very important keyword in JavaScript. This operator specifies that an expression should be evaluated but not return a value.
The syntax format is as follows:
<head> <script type="text/javascript"> <!-- void func() javascript:void func() 或者 void(func()) javascript:void(func()) //--> </script> </head>
The following code creates a hyperlink, and nothing will happen when the user clicks it.
Instance
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>php中文网(php.cn)</title> </head> <body> <a href="javascript:void(0)">单此处什么也不会发生</a> </body> </html>
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When the user links, void(0) evaluates to 0, but has no effect on Javascript.
In the following example, a warning message is displayed after the user clicks the link:
Instance
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文网(php.cn)</title>
<script type="text/javascript">
<!--
//-->
</script>
</head>
<body>
<p>点击以下链接查看结果：</p>
<a href="javascript:void(alert('Warning!!!'))">点我!</a>
</body>
</html>Run Instance»
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In the following examples, parameter a will return undefined:
Instance
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文网(php.cn)</title>
<script type="text/javascript">
function getValue(){
var a,b,c;
a = void ( b = 5, c = 7 );
document.write('a = ' + a + ' b = ' + b +' c = ' + c );
}
</script>
</head>
<body>
<p>点击以下按钮查看结果：</p>
<form>
<input type="button" value="点我" onclick="getValue();" />
</form>
</body>
</html>Run Instance»
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##href="#" and href="javascript:void( 0)"The difference
# contains a location information, and the default anchor is #top, which is the top of the web page.
And javascript:void(0) only represents a dead link. When the page is very long,# will be used to locate the specific location of the page. The format is: # + id.
If you want to define a dead link, please use javascript:void(0).<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>php.cn</title> </head> <body> <a href="javascript:void(0);">点我没有反应的!</a> <a href="#pos">点我定位到指定位置!</a> <br> ... <br> <p id="pos">尾部定位点</p> </body> </html>
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