How to validate Radio button fields in form Either or OR?

Question

I have a radio form elements with other fields as well on a webpage, there have two types of form radio field, one is vegetable and other is meat. I want to select like these "If they select a meat they have to select a veggie but if they only select a veggie they don't have to select a meat" here is the screenshot of these radio fields http://prntscr.com/nhu6ao

jQuery('.radio').change(function() {
  jQuery(this).parent().removeClass('error');
  jQuery(this).parent().parent().removeClass('error');
  if (jQuery(this).hasClass('box-input')) {
    jQuery('#preseason-error').slideUp("slow");
    jQuery('#preseason-title').css("color", "#444");
    jQuery('.boxes-select').removeClass('error');
  }
})

Results will be: If they select a meat they have to select a veggie but if they only select a veggie they don't have to select a meat

Answer 1

Voila!

I have prepped a simple example for you. Before we begin I would like to point out 2 things. It is very inefficient to create an event listener for every form element, as you did by calling the .on('.radio') . Good practice here is to add event listener on the form ( or any other wrapping element - even body ), and than use the event.target as your reference to the form element that was just clicked by the user.

Another thing is that from the UX perspective I would suggest moving the Meat dishes above the Veggies, as it does not make sense to show it as a first choice if Veggies are somehow dependant on Meats.

JSfiddle with working example: https://jsfiddle.net/mkbctrlll/7209ayr3/45/

const $meals = $('#meal-options')

$meals.on('change', function(event) {
    if(event.target.name === 'meat') {
    console.log('Meat selected!')
    $('input[name="veggie"]').attr('required', 'true')
  }
})

<form id="meal-options">
  <h2>
    Meat options
  </h2>

  <label for="radio-1">
    <input id="radio-1" name="meat" type="radio">
    Meat 1
  </label>

  <label for="radio-2">
    <input id="radio-2" name="meat" type="radio">
    Meat 2
  </label>

  <h2>
    Veggie options
  </h2>

  <label for="radio-3">
    <input id="radio-3" name="veggie" type="radio">
    veggie 1
  </label>

  <label for="radio-4">
    <input id="radio-4" name="veggie" type="radio">
    veggie 2
  </label>

  <label for="radio-5">
    <input id="radio-5" name="veggie" type="radio">
    veggie 3
  </label>

  <input type="submit">
</form>