isNumeric javascript

There is no predefined function to test ,if a value is numeric .
This function helps to check whether a variable's value is numeric or not.


var isNumeric = function(x) {
// returns true if x is numeric and false if it is not.
var RegExp = /^(-)?(\d*)(\.?)(\d*)$/;
return String(x).match(RegExp);
}


Hope this helps!