Html select multiple get all values at onchange event

In the example below, i'm builiding arrays of selected options and selected values :

<select id="my-array" multiple>
  <option value="1">1</option>
  <option value="2">2</option>
  <option value="3">3</option>
</select>

const myArray = document.getElementById('my-array');
myArray.addEventListener('change', (e) => {

  const options = e.target.options;
  const selectedOptions = [];
  const selectedValues = [];

  for (let i = 0; i < options.length; i++) {
    if (options[i].selected) {
      selectedOptions.push(options[i]);
      selectedValues.push(options[i].value);
    }
  }

  console.log(selectedOptions);
  console.log(selectedValues);
});

This example might help without jQuery:

function getSelectedOptions(sel) {
  var opts = [],
    opt;
  var len = sel.options.length;
  for (var i = 0; i < len; i++) {
    opt = sel.options[i];

    if (opt.selected) {
      opts.push(opt);
      alert(opt.value);
    }
  }

  return opts;
}

<select name="myarray[]" id="myarray" class="select2-select req" style="width: 90%;" onChange="getSelectedOptions(this)" multiple>
  <option value="1">1</option>
  <option value="2">2</option>
  <option value="3">3</option>
</select>

You can use jquery to solve it:

get_values=function(){
    var retval = [];    
    $("#myarray:selected").each(function(){
        retval .push($(this).val()); 
    });
    return retval;
};