Accept only 0 and 1 in input field

Question

I want to accept only 0 and 1 in input field and add spaces after every 4 digits. With the following I can add spaces but it accepts all digits. How can I restrict it to only 0 and 1 instead of all digits? I'm having difficulty in the pattern.

document.getElementById('num').addEventListener('input', function (e) {
  e.target.value = e.target.value.replace(/[^\d]/g, '').replace(/(.{4})/g, '$1 ').trim();
});

Demo: https://jsfiddle.net/5rvfgpzo/

Sam, do you also expect a fixed number of groups of 4? Or is "1010 01" also valid input? — trincot, Dec 30 '20 at 10:03
in your input field you can say type number min=0 max=1 step=1 then it allows only zero and one — Aalexander, Dec 30 '20 at 10:06
You just have to replace `.replace(/[^\d]/g, '')` with `.replace(/[^0-1]/g, '')` — secan, Dec 30 '20 at 10:07

score 2 · Accepted Answer · answered Dec 30 '20 at 10:11

You can try this :

document.getElementById('num').addEventListener('input', function (e) {

  e.target.value = e.target.value.replace(/[^0-1]/g, '').replace(/(.{4})/g, '$1 ').trim();
});

input {
  width: 200px;
  padding: 5px;
}

<label for="num">num</label>
<input id="num" type="text" min="0" max="1" name="num" maxlength="14" />

Accept only 0 and 1 in input field

1 Answers1