it seems simple, but I couldn't figure how to intercept numbers on javascript from Document DOM

    $(document).keypress(function (e) {
        if (e.keyCode == xx) {
            alert();
        }
    });

it seems simple, but I couldn't figure how to intercept numbers on javascript from Document DOM

    $(document).keypress(function (e) {
        if (e.keyCode == xx) {
            alert();
        }
    });

• javascript
• jquery

4 Answers 4

Numbers are 48 through 57, so...

$(document).keypress(function (e) {
    var key = e.keyCode || e.charCode;
    if (key >= 48 && key <= 57) {
        alert('You pressed ' + (key - 48));
    }
});

See demo

Source: http://www.quirksmode/js/keys.html

Keypress events yield a keyCode of 0 in Firefox, and the ASCII character value everywhere else. Keypress events yield a charCode of the ASCII character value in Firefox. Therefore, you should use (e.keyCode || e.charCode) to get the character value.

Also note that your code also wouldn't work because alert should accept one argument. In Firefox, at least, calling alert with no arguments throws an exception.

With those two issues fixed, your code will now be:

$(document).keypress(function (e) {
    if ((e.keyCode || e.charCode) == <number from 48..57 inclusive>) {
        alert('something');
    }
});

Example: http://jsfiddle/gRrk6/

$(document).keydown(function(event){ if(event.keyCode == 13) { alert('you pressed enter');} }); replace 13 with the keys code, see here for details: http://www.cambiaresearch./articles/15/javascript-char-codes-key-codes

you should notice the differences between events [ keyCode, charCode, which ] and this test page affected by the browser i.e i tested it on safari the onKeyPress always empty

JavaScript Event KeyCode Test Page