JSFiddle - React, Tailwind, and code Playground

HTML

<label><input type="checkbox" name="vehicle" value="Bike"/> Bike</label>
<label><input type="checkbox" name="vehicle" value="Car"/> Car</label>
<label><input type="checkbox" name="vehicle" value="Airplane"/> Airplane</label>

JavaScript

var input = document.getElementsByTagName('input')
,   value = {0:'', 1:'', 2:''}
,   x = input.length--
,   array
,   box
;
function handle (x) {
 input[x].onchange = function () {
    box = input[x];
    value[x] = box.checked ? box.value : '';
    array = [value[0], value[1], value[2]];
    console.log(array);       
 };
}

while (x) handle(--x);