What's the best way to automatically insert slashes '/' in date fields

Question

I\'m trying to add functionality to input date fields so as when the users enters in digits, slashes \"/\" get automatically added.

So suppose I have the following

Answer 1

My regex solution for React:

// add auto "/" for date, i.e. MM/YY
  handleExpInput(e) {

    // ignore invalid input
    if (!/^\d{0,2}\/?\d{0,2}$/.test(e.target.value)) {
      return;
    }

    let input = e.target.value;

    if (/^\d{3,}$/.test(input)) {
      input = input.match(new RegExp('.{1,2}', 'g')).join('/');
    }

    this.setState({
      expDateShow: input,
    });
  }