Wijmo UI for the Web
isValueNull Method
wijmo.input Namespace > wijinputnumber type : isValueNull Method
Determines whether the value is in null state.
Syntax
$(function () {
    var returnsValue; // Type:  bool
    returnsValue = $(".selector").wijinputnumber("isValueNull");
});
function isValueNull() : bool;
See Also

Reference

wijinputnumber type
wijinputnumber jQuery Widget