How do I programmatically set the value of a select box element using JavaScript?
You can use this function:
function selectElement(id, valueToSelect) {
let element = document.getElementById(id);
element.value = valueToSelect;
}
selectElement('leaveCode', '11');
<select id="leaveCode" name="leaveCode">
<option value="10">Annual Leave</option>
<option value="11">Medical Leave</option>
<option value="14">Long Service</option>
<option value="17">Leave Without Pay</option>
</select>
Optionally if you want to trigger onchange event also, you can use :
element.dispatchEvent(new Event('change'))
If you are using jQuery you can also do this:
$('#leaveCode').val('14');
This will select the <option>
with the value of 14.
With plain Javascript, this can also be achieved with two Document
methods:
With
document.querySelector
, you can select an element based on a CSS selector:document.querySelector('#leaveCode').value = '14'
Using the more established approach with
document.getElementById()
, that will, as the name of the function implies, let you select an element based on itsid
:document.getElementById('leaveCode').value = '14'
You can run the below code snipped to see these methods and the jQuery function in action:
const jQueryFunction = () => {
$('#leaveCode').val('14');
}
const querySelectorFunction = () => {
document.querySelector('#leaveCode').value = '14'
}
const getElementByIdFunction = () => {
document.getElementById('leaveCode').value='14'
}
input {
display:block;
margin: 10px;
padding: 10px
}
<select id="leaveCode" name="leaveCode">
<option value="10">Annual Leave</option>
<option value="11">Medical Leave</option>
<option value="14">Long Service</option>
<option value="17">Leave Without Pay</option>
</select>
<input type="button" value="$('#leaveCode').val('14');" onclick="jQueryFunction()" />
<input type="button" value="document.querySelector('#leaveCode').value = '14'" onclick="querySelectorFunction()" />
<input type="button" value="document.getElementById('leaveCode').value = '14'" onclick="getElementByIdFunction()" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>