JSFiddle - React, Tailwind, and code Playground

HTML

<select multiple id="multiple">
    <option value="1" type="Alice" selected="selected">Option 1</option>
    <option value="2" type="Bob">Option 2</option>
    <option value="2" type="Peter">Option 2</option>
    <option value="2" type="John" selected="selected">Option 2</option>
    <option value="2" type="Bill" selected="selected">Option 2</option>    
</select>

JavaScript

var t = document.getElementById('multiple');
var a = [];
for(i = 0; i < t.length; i++){
    if(t[i].selected){
        a.push(t[i].getAttribute('type'));
        alert(t[i].getAttribute('type'));
    }
}