Memo: void meaning in javascript

When debugging CGI today, it is clear that the CGI program has been executed and the final result is correct, but the page is not refreshed. The test results in FireFox2.0 are normal, but IE6 is not refreshed! After careful investigation, we found that the cgi page is linked to <a href = "javaScript: void (0)" OnClick = "XXX_Func ();"...> Only a sample </a>, the problem lies in this void (0!

Let's take a look at the meaning of void (0) in JavaScript:

In JavaScript, void is an operator that specifies to calculate an expression but does not return a value.
The format of the void operator is as follows:
1. javascript: void (expression)
2. javascript: void expression
Expression is a standard JavaScript expression to be calculated. Parentheses outside the expression are optional, but it is a good habit to write. You can use the void operator to specify a hyperlink. The expression is calculated, but no content is loaded in the current document. The code above creates a hyperlink, and nothing will happen after the user clicks. When a user clicks a link, void (0) is calculated as 0, but it has no effect on JavaScript.

<A href = "javascript: void (0)"> click here. </a>

That is to say, some processing needs to be executed,When the page is not refreshed as a whole, You can use void (0), but when you need to refresh the page, it should be careful.

In fact, we can use <a href = "javascript: void (document. form. submit ()"> to perform a submit operation. Under what circumstances will void (0) be used more often, without refreshing the new version? Of course it is Ajax. If you look at Ajax web pages, you will usually see a lot of void (0 ), :), so before using void (0), you 'd better think about whether the page needs to be refreshed as a whole.