This operator allows inserting expressions that produce side effects
into places where an expression that evaluates to undefined is
The void operator is often used merely to obtain the undefined
primitive value, usually using void(0) (which is equivalent to void
0). In these cases, the global variable undefined can be used instead
(assuming it has not been assigned to a non-default value).
void is an operator that is used to return a undefined value so the browser will not be able to load a new page. An important thing to note about the void operator is that it requires a value and cannot be used by itself.
<input type=submit value=submit onClick=return false; />