I'm seeing a wierd issue in javascript, or maybe it's because javascript is new to me.
I am trying to allow some action if onkeypress, but only when alphanumeric or special character is pressed. This is my code:
if(e.keyCode>=32 && e.keyCode<=126 ){
alert(e.keyCode);}
}
It does not alert if I press any special character key like {,]>. am I missing anything here?
The keyCode for a comma (,) is 188. Could this be why?
http://www.cambiaresearch.com/articles/15/javascript-char-codes-key-codes
keyCode is not a reference into the ASCII table
keyCode.You have assumed that keyCode gives you an ASCII index, but that is not true. Your range criteria are incorrect due to this assumption.
In a
keypressevent, the Unicode value of the key pressed is stored in either thekeyCodeorcharCodeproperty, never both. If the key pressed generates a character (e.g. 'a'),charCodeis set to the code of that character, respecting the letter case. (i.e.charCodetakes into account whether the shift key is held down). Otherwise, the code of the pressed key is stored inkeyCode.
keyCodeis always set in the keydown and keyup events. In these cases, charCode is never set.To get the code of the key regardless of whether it was stored in
keyCodeorcharCode, query the which property.For a list of the keyCode values associated with particular keys, run the example in Example 7: Displaying Event Object Constants and view the resulting HTML table.
Doing as instructed reveals that some of your "special" characters lie outside of the range limits you've specified.
Kevin also pointed out this useful table, but you'd be best off using a more canonical approach to keypress handling.
You need to use the which property in most browsers and keyCode in IE only. You do have the correct event: only keypress will do if you're interested in the character typed rather than the physical key pressed.
Here's my favourite reference for this stuff: http://unixpapa.com/js/key.html
document.onkeypress = function(e) {
e = e || window.event;
var charCode = (typeof e.which == "number") ? e.which : e.keyCode;
var charTyped = String.fromCharCode(charCode);
alert("Character typed: " + charTyped);
};
You should use which, it should work in both Firefox and Chrome.
Try this:
document.onkeypress = function(e) {
console.log(e.keyCode + " -- " + e.which + " -- " + e.charCode);
if(e.which >= 32 && e.which <= 126 ){
alert(e.which);
}
};
