MouseEvent.altKey
The MouseEvent.altKey
read-only property is a
Boolean
that indicates whether the alt key was pressed or not
when a given mouse event occurs.
Be aware that the browser can't always detect the alt key on some operating systems. On some Linux variants, for example, a left mouse click combined with the alt key is used to move or resize windows.
Note: On Macintosh keyboards, this key is also known as the option key.
Syntax
var altKeyPressed = instanceOfMouseEvent.altKey
Return value
A Boolean
, where true
indicates that the key is pressed, and
false
indicates that the key is not pressed.
Example
This example logs the altKey
property when you trigger a
click
event.
HTML
<p>Click anywhere to test the <code>altKey</code> property.</p>
<p id="log"></p>
JavaScript
let log = document.querySelector('#log');
document.addEventListener('click', logKey);
function logKey(e) {
log.textContent = `The alt key is pressed: ${e.altKey}`;
}
Result
Specifications
Specification | Status | Comment |
---|---|---|
Document Object Model (DOM) Level 3 Events Specification The definition of 'MouseEvent.altkey' in that specification. |
Obsolete | No change from Document Object Model (DOM) Level 2 Events Specification. |
Document Object Model (DOM) Level 2 Events Specification The definition of 'MouseEvent.altkey' in that specification. |
Obsolete | Initial definition. |
Browser compatibility
BCD tables only load in the browser