KeyboardEvent.charCode - Web APIs 编辑

Non-standard

This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

Deprecated

This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The charCode read-only property of the KeyboardEvent interface returns the Unicode value of a character key pressed during a keypress event.

Do not use this property, as it is deprecated. Instead, get the Unicode value of the character using the key property.

Syntax

var code = event.charCode;

Return value

A number that represents the Unicode value of the character key that was pressed.

Example

HTML

<p>Type anything into the input box below to log a <code>charCode</code>.</p>
<input type="text" />
<p id="log"></p>

JavaScript

let input = document.querySelector('input');
let log = document.querySelector('#log');

input.addEventListener('keypress', function(e) {
  log.innerText = `Key pressed: ${String.fromCharCode(e.charCode)}\ncharCode: ${e.charCode}`;
});

Result

Notes

• In a keypress event, the Unicode value of the key pressed is stored in either the keyCode or charCode property, but never both. If the key pressed generates a character (e.g., 'a'), charCode is set to the code of that character; charCode respects the letter case (in other words, charCode takes into account whether the shift key is held down). Otherwise, the code of the pressed key is stored in keyCode.
• When one or more modifier keys are pressed, there are some complex rules for charCode. See Gecko Keypress Event for details.
• charCode is never set in the keydown and keyup events. In these cases, keyCode is set instead.
• To get the code of the key regardless of whether it was stored in keyCode or charCode, query the which property.
• Characters entered through an IME do not register through keyCode or charCode. Actually with the Chinese IME I'm using, entering the IME results in a keypress event with keyCode = 229 and no other key events fire until the IME exits (which may happen after multiple characters are inputted). I'm not sure if other IME's work this way.
• For a list of the charCode values associated with particular keys, run Example 7: Displaying Event Object Properties and view the resulting HTML table.

Specifications

Browser compatibility

BCD tables only load in the browser