The use of javascript void (0)

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, if you want to perform some processing, but do not refresh the page as a whole, you can use void (0). However, when you need to refresh the page, you have to be careful.

When calling the custom JS function, if we use <a href = "#" onclick = "method;"> click </a>, although the method can be executed, however, if the page contains a scroll bar, it will automatically scroll to the top of the page. If we use <a href = "javascript: void (0); onclick =" method; "> click </a>: The page does not scroll during execution. This is useful for image switching and AJAX calling.