Event keyCode property

Examples

Being Unicode values by pressing the keys on the keyboard:

var x = event.keyCode;

x The output is:

119 // 119 is the character "w"

try it"

Bottom of this article contains more examples.

Definitions and use

keyCode property returns onkeypress event trigger key character code value or onkeydown or onkeyup event key code.

Is the difference between the two types of code:

Character code - Indicates an ASCII character
Keyboard codes - represents the number keys on the keyboard real

p> two types of values are not equal, for example, lowercase characters "w" and uppercase "W" have the same keyboard code because they are on the keyboard ( "W" code "87"), but they have their different character code, two characters are not the same output ( "w" and "W" character code "119" and "87") - See the following examples may be better understood.

Tip: If you need to know the user presses the print key (such as "a" or "5"), it is recommended to use onkeypress event. If you need to know the user presses a function key (such as "F1", "CAPS LOCK" or "Home") can be used onkeydown or onkeyup event.

Note: In Firefox ,, keyCode property onkeypress event is invalid (return 0). Browser compatibility issues, can be used with which and keyCode properties to solve:

var x = event.which || event.keyCode; // use which or keyCode, this may support different browsers

Note: A list of all Unicode characters can see our complete Unicode reference manual .

Tip: If you need to convert Unicode character value, you can use fromCharCode () method.

Note: This property is read-only.

Note: which keyCode property and provides a solution method for browser compatibility, the latest version of the DOM event recommended key attribute as an alternative method.

Tip: If you want to see if the press "ALT", "CTRL", "META" or "SHIFT" key, you can use altKey , ctrlKey , metakey or shiftKey property.

Browser Support

Attributes
keyCode	Yes	Yes	Yes	Yes	Yes

grammar

event .keyCode

technical details

return value:	Number that represents the Unicode character code or Unicode key code
DOM version:	DOM Level 2 Events

More examples

Examples

Use onkeypress and onkeydown to demonstrate the difference between character code and keyboard codes:

<input type = "text" onkeypress = "uniCharCode (event)" onkeydown = "uniKeyCode (event)">

function uniCharCode (event) {
var char = event.which || event.keyCode;
document.getElementById ( "demo") .innerHTML = "Unicode CHARACTER code:" + char;
}

function uniKeyCode (event) {
var key = event.keyCode;
document.getElementById ( "demo2") .innerHTML = "Unicode KEY code:" + key;
}

When pressed on the keyboard "a" key (do not use Caps Lock), the output results are as follows:

Unicode character code: 97
Unicode key code: 65

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Examples

If you press the Esc key to pop up a message:

<input type = "text" onkeydown = "myFunction (event)">

function myFunction (event) {
var x = event.keyCode;
if (x == 27) {// 27 ESC key is
alert ( "You pressed the Escape key !");
}
}

try it"