Question

following is my piece of code which checks if the input format is EMAIL which comes from the form input or not and validates accordingly i want to know how can i modify the following code that validates if the input was only number

  if(email.length == 0 || email.indexOf('@') == '-1'){
                var error = true;
                $('#email_error').fadeIn(500);
            }else{
                $('#email_error').fadeOut(500);
            }

Answer 1

I would use:

if(isNaN(email*1)){
    //evaluated to NaN
}else{
    //evaluated to number
}

In this case the (email*1) have the possibility to evaluate to NaN, and thus will fail the check because the list of falsish values are 0,"",false,null,undefined,NaN