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. (Implement version Navigator 3.0)
You can use the void operator to specify a hyperlink. The expression is calculated, but no content is loaded in the current document.
The following code creates a hyperlink. Nothing happens after you click it. 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>
The following code creates a hyperlink. When you click it, the form is submitted.
<A href = "javascript: void (document. form. submit ()">