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How to differeniate capital letters from lower ones in onkeydown event handler method

Answer 1

A:

It looks to me like you answered your own question. If you are detecting the SHIFT key, you can easily differentiate between capital and lowercase:

if(e.shiftKey){
   alert("You pressed a CAPITAL letter with the code " + e.keyCode);
}else{
   alert("You pressed a LOWERCASE letter with the code " + e.keyCode);
}

Or am I misunderstanding your question?

Update: Upper case ASCII codes can easily be converted to lower case ASCII codes by adding 32, so all you need to do is this:

<html>
<head>
<title>Test</title>

<script type="text/javascript">

function showChar(e){
  if(e.keyCode!=16){ // If the pressed key is anything other than SHIFT
        if(e.keyCode >= 65 && e.keyCode <= 90){ // If the key is a letter
            if(e.shiftKey){ // If the SHIFT key is down, return the ASCII code for the capital letter
                alert("ASCII Code: "+e.keyCode);
            }else{ // If the SHIFT key is not down, convert to the ASCII code for the lowecase letter
                alert("ASCII Code: "+(e.keyCode+32));
            }
        }else{
            alert("ASCII Code (non-letter): "+e.keyCode);
        }
  }
}

</script>
</head>

<body onkeydown="showChar(event);">
<p>Press any character key, with or without holding down
 the SHIFT key.<br /></p>
</body>
</html>

Update 2: Try this:

<html>
<head>
<title>Test</title>

<script type="text/javascript">

function showChar(e){
  if(e.keyCode!=16){ // If the pressed key is anything other than SHIFT
        c = String.fromCharCode(e.keyCode);
        if(e.shiftKey){ // If the SHIFT key is down, return the ASCII code for the capital letter
            alert("ASCII Code: "+e.keyCode+" Character: "+c);
        }else{ // If the SHIFT key is not down, convert to the ASCII code for the lowecase letter
            c = c.toLowerCase(c);
            alert("ASCII Code: "+c.charCodeAt(0)+" Character: "+c);
        }
  }
}

</script>
</head>

<body onkeydown="showChar(event);">
<p>Press any character key, with or without holding down
 the SHIFT key.<br /></p>
</body>
</html>

Computerish 2010-06-26 22:51:00

But should not the keyCode change, too? I need to get the difference from keyCode or something else as a value. In both examples the keyCode is same. I seek a way that provides a different keyCodes for capital A and lowercase a pressed.

Valentina Tatya 2010-06-26 23:04:58

Take a look at the update to my answer above. I think that's what you are looking for.

Computerish 2010-06-27 04:13:29

Thanks that is pretty close to my need. But how can I add support to UTF-8? Say for capital Ü and smallcase ü throws the "ASCII Code (non-letter)" alert. Is it possible to differentiate Unicode captial latters from smallcase letters in onkeydown.

Valentina Tatya 2010-06-27 13:46:17

I added some more code. I don't know if that will work, but it might.

Computerish 2010-06-27 23:22:22

The reason that the keyCode is a keyCode instead of a character code is that the keyCode is a keyCode representing which KEY is pressed. The key by itself doesn't say whether the character will be uppercase or numeric or punctuation or whatever. Also the key by itself doesn't say whether CAPS LOCK is active, but if CAPS LOCK is active then the presence of a Shift key bit will indicate the opposite of what this code is doing.

Windows programmer 2010-06-27 23:46:47

Windows programmer is correct, but I am not aware of a way to detect the CAPS LOCK key in JavaScript. If caps lock support is required, you would be better off having the user type into a text box and checking what they type.

Computerish 2010-06-27 23:55:25

Computerish, it partially works but I think that is the best solution that can be achieved. Thanks for your help.

Valentina Tatya 2010-06-28 13:49:07

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How to differeniate capital letters from lower ones in onkeydown event handler method

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