Question

155

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

rated 0 times [ 162] [ 7] / answers: 1 / hits: 21649 / 14 Years ago, sat, june 26, 2010, 12:00:00

<html>

<head>

<title>Test</title>



<script type=text/javascript>



function showChar(e) {

    if (e.keyCode != 16) {

        alert(

           keyCode:  + e.keyCode + n

          + SHIFT key pressed:  + e.shiftKey + n

        );

    }

}



</script>

</head>



<body onkeydown=showChar(event);>

<p>Press any character key, with or without holding down

 the SHIFT key.<br /></p>

</body>

</html>

How can I differentiate capital A from lowercase a in onkeydown event handler method? Above algorithm fires the same keyCode value. I need to detect the capital letters when they are pressed in onkeydown.

Note: The code contains an exception for SHIFT key. Otherwise it does not allow to type capital letters. BTW, I need to use onkeydown for my trial.

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jacklynr

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4 Years ago

answered 14 Years ago emiliano · Accepted Answer

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>