Block +,-,e in input type number

The default behavior if you don't like the incoming key value:

HTML::

<input type="number" class="classname">

SCRIPT::

<script>
     document.querySelector(".classname").addEventListener("keypress", function (evt) {
       if (evt.which != 8 && evt.which != 0 && evt.which < 48 || evt.which > 57)
      {
         evt.preventDefault();
      }
     });

      // 0 for null values
     // 8 for backspace
    // 48-57 for 0-9 numbers
</script>