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javascriptformsvalidationuser-input

Maximum two decimal, check on input not working properly

I needed a function in JavaScript that limited the input (form) of a number of a maximum of two decimals. So I found the following online:

function restrict(tis) {
  var prev = tis.getAttribute("data-prev");
  prev = (prev != '') ? prev : '';
  if (Math.round(tis.value * 100) / 100 != tis.value)
    tis.value = prev;
  tis.setAttribute("data-prev", tis.value)
}
<input type="number" name="amount" step="any" oninput="restrict(this);" required>

Honestly It's amazing, the input doesn't allow you more than two decimals, until by chance I entered only zeros, like this "100.000000000", if you enter only zeros as decimals it doesn't limit the field...

Is there anybody that has a fix for this? Thank you very much!

Elliot

Solution

  • I borrowed the regex from the other answer

    function restrict(tis) {
  let prev = tis.getAttribute("data-prev");
  prev = (prev != '') ? prev : '';
  if (!tis.value.match(/^\d*(\.\d{0,2})?$/))
    tis.value = prev;
  tis.setAttribute("data-prev", tis.value)
}
    <input type="number" name="amount" step="any" oninput="restrict(this);" required>