Format input text with regular expressions in javascript

Question

I need to format an input text like this: 2342452-1. After typing seven numbers I need to add a dash (-) and then a number again. Is there a simple way of doing this in javaScript?

Yes, using either a search engine like Google or the search field from SO `(:` — Ele, Sep 23 '18 at 01:07
Take a look at [input-mask](https://github.com/RobinHerbots/Inputmask), this helps me a lot on putting masks in input fields. — Shidersz, Sep 23 '18 at 01:10

score 1 · Accepted Answer · answered Sep 23 '18 at 01:23

You can check the length and use indexOf to find if this string contains a '-'

function maskinput(e) {
  if (e.target.value.length > 7 && e.target.value.indexOf('-') === -1) {
    let substring1 = e.target.value.slice(0, 7),
      substring2 = e.target.value.slice(7, e.target.value.length);
    e.target.value = substring1 + '-' + substring2;
  }
}

<input type='text' onkeyup='maskinput(event)'>

Format input text with regular expressions in javascript

1 Answers1