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 to calculate an expression but does 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>
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>php中文網(wǎng)(php.cn)</title> </head> <body> <a href="javascript:void(0)">點(diǎn)擊此處什么也不會發(fā)生</a> </body> </html>
When the user links, void(0) evaluates to 0, but Nothing works on Javascript.
In the following example, a warning message is displayed after the user clicks the link:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文網(wǎng)(php.cn)</title>
<script type="text/javascript">
</script>
</head>
<body>
<a href="javascript:void(alert('有誤'))">點(diǎn)擊</a>
</body>
</html>In the following example, parameter a will return undefined:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文網(wǎng)(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>
<form>
<input type="button" value="單擊" onclick="getValue();" />
</form>
</body>
</html>The difference between href="#" and href="javascript:void(0)"
# contains a location information, the default anchor is #top, which is the web page the upper end.
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).
<a href="javascript:void(0);">點(diǎn)擊沒反應(yīng)</a> <a href="#pos">單擊跳轉(zhuǎn)</a> <br> ... <br> <p id="pos">尾部定位點(diǎn)</p>
