Why 'keydown' event works like 'keypress' event?
Question
The next sample code outputs 'keydown' message many times while I hold a button down. The docs says that the keydown event happens once for one push of the button. So, the keydown event works like the keypress event in the next example.
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<title></title>
<script type='text/javascript' src='jquery.js'></script>
<script type='text/javascript'>
function onLoad()
{
$( '#text' ).on( 'keydown', function() { console.info( 'keydown' ) } );
}
</script>
</head>
<body onload='onLoad()'>
<input type='text' id='text'>
</body>
</html>
I tested it on Windows, Firefox 19.0.2 and Google Chrome 25.0.1364.152. Also I created a fiddle (the problem can be reproduced). JQuery versions for which problem is reproduced: 1.8.2, 1.9.1.
Update.
I did realize the problem: How can I avoid autorepeated keydown events in JavaScript? .
4 answers
solution1
26 ACCPTED 2013-03-09 12:31:35
The
keydownevent occurs when the key is pressed, followed immediately by thekeypressevent. Then thekeyupevent is generated when the key is released.In order to understand the difference between
keydownandkeypress, it is useful to understand the difference between a "character" and a "key". A "key" is a physical button on the computer's keyboard while a "character" is a symbol typed by pressing a button. In theory, thekeydownandkeyupevents represent keys being pressed or released, while thekeypressevent represents a character being typed. The implementation of the theory is not same in all browsers.
solution2
11 2013-03-09 12:35:02
The KeyPress event is not raised by noncharacter keys; however, the noncharacter keys do raise the KeyDown and KeyUp events.
Key events occur in the following order:
- KeyDown
- KeyPress
- KeyUp
Are these events available on the Window, Document, Form, focusable elements
Test Page
solution3
1 2013-03-09 12:30:15
按下键时会发生keydown事件，紧接着是按下按键事件。
solution4
1 2016-01-07 19:15:13
i have answer here, following me slowly: keydown : working when you start typing key or start to change something and keydown give you one result for one press but give you the result before the last one not last result. keyup : working when you stop typing a key or go back (change something like remove character) and it's give give you last result. keypress : working when you start typing key but not start to change something and keydpress give you one result for one press but give you the result before the last ,which (lastResult - 1)
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