This code is often visible in JavaScript scripts:
〈a href= "Javascript:changenum (); void (0);" 〉here〈/a〉
But what does void (0) mean here?
In JavaScript, Void is an operator that specifies that you want to evaluate an expression but not return a value.
void operator usage format is as follows:
1. javascript:void (expression)
2. Javascript:void expression
Expression is an expression of the JavaScript standard to compute. The parentheses outside the expression are optional, but writing is a good habit. You can use the void operator to specify a hyperlink. The expression is evaluated but does not load any capacity in the current document.
The following code creates a hyperlink that will not happen when the user clicks on it. When the user clicks on the link, void (0) evaluates to 0, but there is no effect on JavaScript.
<a href= "javascript:void (0)" > Click here Nothing will happen </A>
The following code creates a hyperlink that submits the form when the user clicks it.
<a href= "Javascript:void (Document.form.submit ())" > Click here to submit the form </A>
When using JavaScript, we typically invoke JavaScript methods via a pseudo link, like <a href= "#" onclick= "javascript: Method" > Submit </a>. One problem with this approach is that while clicking on the link does not jump the page, the scroll bar rolls up, and the solution is to return a false.
As shown below:
<a href= "#" onclick= "javascript: method; return false;" > Submit </a>
<a href= "javascript:void (0)" onclick= "javascript: method; return false;" > Submit </a>
<a href= "#this" onclick= "javascript: Methods" >xx</a>
# contains a location information the default anchor point is #top, which is the top of the page, and javascript:void (0) only represents a dead link. This is why sometimes the page is very long browsing links obviously is # but it beats to the top of the page, and javascript:void (0) is not so it is best to invoke a script with void (0).
So we do not refresh the page with void (0) More, is generally Ajax, look at Ajax Web pages, the general will see a lot of void (0), so in the use of void (0), it is best to think about whether the page needs to be a whole refresh.
