HTMLSelectElement.selectedIndex

The HTMLSelectElement.selectedIndex is a long that reflects the index of the first or last selected <option> element, depending on the value of multiple. The value -1 indicates that no element is selected.

Syntax

var index = selectElem.selectedIndex;
selectElem.selectedIndex = index;

Example

HTML

<p id="p">selectedIndex: 0</p>

<select id="select">
  <option selected>Option A</option>
  <option>Option B</option>
  <option>Option C</option>
  <option>Option D</option>
  <option>Option E</option>
</select>

JavaScript

var selectElem = document.getElementById('select')
var pElem = document.getElementById('p')

// When a new <option> is selected
selectElem.addEventListener('change', function() {
  var index = selectElem.selectedIndex;
  // Add that data to the <p>
  pElem.innerHTML = 'selectedIndex: ' + index;
})

Specifications

Specification
HTML Standard # dom-select-selectedindex-dev

Browser compatibility

BCD tables only load in the browser