The
voidoperator evaluates the given expression and then returnsundefined.The
voidoperator is often used merely to obtain theundefinedprimitive value, usually using “void(0)” (which is equivalent to “void 0”). In these cases, the global variableundefinedcan be used instead (assuming it has not been assigned to a non-default value).
An explanation is provided here: void operator.
The
voidoperator evaluates the given expression and then returnsundefined.The
voidoperator is often used merely to obtain theundefinedprimitive value, usually using “void(0)” (which is equivalent to “void 0”). In these cases, the global variableundefinedcan be used instead (assuming it has not been assigned to a non-default value).
An explanation is provided here: void operator.
The reason you’d want to do this with the href of a link is that normally, a javascript: URL will redirect the browser to a plain text version of the result of evaluating that JavaScript. But if the result is undefined, then the browser stays on the same page. void(0) is just a short and simple script that evaluates to undefined.