Javascript – Disallow comma character using regex and accept other characters, limit is 1 character in my input box

You can use a regular expression to restrict the comma character and accept other characters. Here’s how you can do it in JavaScript:

const inputBox = document.querySelector('#inputBox');

inputBox.addEventListener('input', function(e) {
  const regex = /^[^,]{0,1}$/;
  if (!regex.test(e.target.value)) {
    e.target.value = e.target.value.substring(0, e.target.value.length - 1);
  }
});

In this code, inputBox is assumed to be the ID of your input element. The input event listener is added to the input box. The regular expression ^[^,]{0,1}$ matches any string of length 0 or 1 that does not contain a comma. If the input does not match this regular expression, the last character of the input is removed.

Please replace #inputBox with the actual ID of your input element.