indeterminate

by jdanyow

HTML

<label>
    <input id="test" type="checkbox" />
    value: <span id="value"></span>
</label>

JavaScript

span = document.getElementById('value');

checkbox = document.getElementById('test');
checkbox.indeterminate = true;

function displayValue() {
  value.textContent = checkbox.checked;
}

displayValue();

checkbox.addEventListener('change', displayValue);