jquery replace character when keypress

I'm searching to make an input with default value 0.00

When you try to write a number let say 6, in input to appear 0.06 next 62, to appear 0.62 ... Maximum 3 digits separated by dot after first digit ...

I saw something like this on Phone IMEI check, but I don't remember where ... 13 digits 0 and when you write a digit it replace last one with new digit

I didn't know how to search something like this ...

Thanks and sorry if it's a stupid question.

Stefan

Solution

I hope this will solve your problem. I have used event.key on keyup event to determine which key is pressed and then processed the input data shows the result.

var result = 0;
$(document).ready(function() {
  $("input").keyup(function(event) {
    var k = event.key;
    if (!isNaN(k)) { //check if input is a number
      if((parseFloat(result)) < 1) { //condition to keep result in maximum of 3 digit
        result = parseFloat(result*1000) + parseFloat(k);
        result /= 100;
        result = result.toFixed(2); //Convert into a string, keeping only two decimals
        $("input").val(result);
      } else {
        $("input").val(result);
      }
    } else if (k == "Backspace" || k == "Delete") { //check if backspace or delete is pressed
      result = 0;
      $("input").val("0.00");
    } else { //check if any non-numeric key pressed
      $("input").val(parseFloat(result).toFixed(2));// assures that always shows formatted result
    }
  });
});

<!DOCTYPE html>
<html>
<head>
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
</head>
<body>
  Enter number:
  <input type="text" placeholder="0.00" autofocus>
</body>
</html>