HTMLSelectElement: selectedIndex property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The selectedIndex property of the HTMLSelectElement interface is the numeric index of the first selected <option> element in a <select> element, if any, or −1 if no <option> is selected. Setting this property selects the option at that index and deselects all other options, while setting it to -1 deselects any currently selected options.

Value

A number.

Examples

HTML

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

js
const selectElem = document.getElementById("select");
const pElem = document.getElementById("p");

// When a new <option> is selected
selectElem.addEventListener("change", () => {
  const index = selectElem.selectedIndex;
  // Add that data to the <p>
  pElem.textContent = `selectedIndex: ${index}`;
});