MouseEvent.altKey

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨2015年7月⁩.

MouseEvent.altKey 只读属性是一个Boolean变量。当事件触发时，如果alt 被按下，则返回 true，否则返回 false。

示例

<html>
<head>
<title>altKey example</title>

<script type="text/javascript">

function showChar(e){
  alert(
    "Key Pressed: " + String.fromCharCode(e.charCode) + "\n"
    + "charCode: " + e.charCode + "\n"
    + "ALT key pressed: " + e.altKey + "\n"
  );
}

</script>
</head>

<body onkeypress="showChar(event);">
<p>
Press any character key,
with or without holding down the ALT key.<br />
You can also use the SHIFT key together with the ALT key.
</p>
</body>
</html>