How can I control decimal field to allow enter more than one point?

Question

I have a field that I can control that not accepts letters etc. I allow to enter "." In order to input decimals. How can I control that not more than one "."?

Here my source code:

$(".allow_decimal").on("input", function(evt) {
   var self = $(this);
   self.val(self.val().replace(/[^0-9\.]/g, ''));
   if ((evt.which != 46 || self.val().indexOf('.') != -1) && 
       (evt.which < 48 || evt.which > 57)) 
   {
     evt.preventDefault();
   }
});

Answer 1

The HTML5 specification allows for a number input type. One of the attributes allowed for the number input is step which is the increments that the number may go up/down in:

 <form> <input type="number" step="0.1" /> <input type="submit"> </form> 

While, yes, you can type in something like '2.25', when you try to submit the form, any HTML5 compliant browser will tell you off for it:

This only applies to HTML5 compliant browsers: CanIUse.com

As always - don't trust anything sent by a user - ALWAYS validate on the server ;)