event.which

Categories: Events > Event Object

event.whichReturns: Number

Description: For key or mouse events, this property indicates the specific key or button that was pressed.

  • version added: 1.1.3event.which

The event.which property normalizes event.keyCode and event.charCode. It is recommended to watch event.which for keyboard key input. For more detail, read about event.charCode on the MDN.

event.which also normalizes button presses (mousedown and mouseupevents), reporting 1 for left button, 2 for middle, and 3 for right. Use event.which instead of event.button.

Examples:

Log which key was depressed.

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<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>event.which demo</title>
  <script src="https://code.jquery.com/jquery-3.7.1.js"></script>
</head>
<body>
 
<input id="whichkey" value="type something">
<div id="log"></div>
 
<script>
$( "#whichkey" ).on( "keydown", function( event ) {
  $( "#log" ).html( event.type + ": " +  event.which );
});
</script>
 
</body>
</html>

Demo:

Log which mouse button was depressed.

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<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>event.which demo</title>
  <script src="https://code.jquery.com/jquery-3.7.1.js"></script>
</head>
<body>
 
<input id="whichkey" value="click here">
<div id="log"></div>
 
<script>
$( "#whichkey" ).on( "mousedown", function( event ) {
  $( "#log" ).html( event.type + ": " +  event.which );
});
</script>
 
</body>
</html>

Demo: