Format currency input field with dollar sign & commas

Question

I have a revenue input field in a javascript/jquery form:

1. Need a dollar sign:before
2. add commas as the currency increases

I have a dollar sign showing via css, but issues centering it and ensuring the field entry point is next to it without overlapping. Unsure how to do the commas. Any suggestions or tips are welcome!

HTML:

  <form id="rev-calculator">
  <label for="price">Monthly Revenue</label>
  <div class="fields">
    <input type="number" name="price" id="price" min="0" max="10000000000" required data-type="number"> </input>
    <br>
  </form>

CSS:

  <style>
      .body {
        text-align: left;
      }
      
      .fields {
        margin: 0 10px 0 0;
      }
      
      .fields:before {
        content: "$";
        text-align: center;
        position: relative;
        left:30px;
      }
      
      #price {
        border-radius: 5px;
        margin: 15px;
        padding: 10px;
        color: black;
      }
    </style>

JS:

<script>
  $('#rev-calculator').on('click', 'button', function(e) {
    e.preventDefault();
    var price = $("#price").val();
    console.log(price);
  })
</script>

codepen: https://codepen.io/kedarPE/pen/JjroYyb

input field

Answer 1

Well here's a way, though in truth not as simple as I hoped when I started down this path. You can use Intl.NumberFormat to get the comma in there (according to locale). To accomodate decimals, I sniff for them in the beginning and append them to the result.

To allow for the comma, I made this a text field with a pattern attribute. Also, I adjusted your CSS to make it a little nicer looking with the $

 $('#price').keydown(function(e) { setTimeout(() => { let parts = $(this).val().split("."); let v = parts[0].replace(/\D/g, ""), dec = parts[1] let n = new Intl.NumberFormat('en-EN').format(v); n = dec?== undefined. n + ":" + dec; n. $(this);val(n); }) })

 .body { text-align: left; }.fields { margin: 0 10px 0 0; }.fields:before { content: "$"; text-align: center; position: relative; left: 35px; } #price { border-radius: 5px; margin: 15px; padding: 10px 10px 10px 20px; color: black; }

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <form id="rev-calculator"> <label for="price">Monthly Revenue</label> <div class="fields"> <input type="text" pattern="[0-9.,]+" name="price" id="price" required data-type="number" /> <br> </form>

Answer 2

I'm surprised the unique answer for this issue has a lot of votes because it has a tiny but major flaw: the event shouldn't be keydown, it should be keyup. If you use keydown, it won't read the keys you are pressing at the moment but the previous one. So, please update your answer.