[RESOLVED] ascii code [javascript]

**Aash** · Jul 31st, 2011, 06:04 AM

hi,
I want to know how to get ascii code for a letter, can anyone will tell me?
i searched a lot but couldn't find the javaScript functions..

thanks..

**akhileshbc** · Jul 31st, 2011, 06:29 AM

Check this: http://jalaj.net/2007/03/08/asc-and-chr-in-javascript/

Example:

html Code:

<html>
<body>
 
<script type="text/javascript">
 
var txt = "A";
document.write(txt.charCodeAt(0));
 
</script>
 
</body>
</html>

It will return 65

**Aash** · Jul 31st, 2011, 06:43 AM

Originally Posted by akhileshbc

Check this: http://jalaj.net/2007/03/08/asc-and-chr-in-javascript/

Example:

html Code:

<html>
<body>
 
<script type="text/javascript">
 
var txt = "A";
document.write(txt.charCodeAt(0));
 
</script>
 
</body>
</html>

It will return 65

thanks

i had seen that web page before.
i'm reading character by character and want to check. Can u tell me where i'm wrong?

Code:

<html>
<head>
<title>verify</title>
<script>
function check()
{
	var str=document.my.first.value;
		for(i=0; i<=str.length; i++)
		{
			if((str.charCodeAt(i)>=48 && str.charCodeAt(i)<=57) || (str.charCodeAt(i)>=97 && str.charCodeAt(i)<=122))
			{
					alert("valid");
					break;
			}
			else
			{
				alert("Invalid");
				break;
			}	
		}		
	
}
</script>
</head>
<body>
<form name=my id="my">
<table>
	<tr>
	<td><input type='text' name='first'></td><td></td>
	</tr>
	<tr>
	<td><input type='button' name='click' value='check ' onClick='check()'></td>
	</tr>
</table>

</body>
</html>

**akhileshbc** · Jul 31st, 2011, 06:46 AM

Use

Code:

str.length-1

Because the array starts from 0. So the upperbound would be 1 less than the length.

If you still get any problems, let me know the input value you have given.

**Aash** · Jul 31st, 2011, 06:51 AM

no, it says valid for , . e.t.c
i want to limit my characters from a to z and from 0 to 9.

**akhileshbc** · Jul 31st, 2011, 06:52 AM

Code:

<html>
<head>
<title>verify</title>
<script>
function check()
{
	var str=document.my.first.value;
var f=0;
		for(i=0; i<=str.length-1; i++)
		{
			if((str.charCodeAt(i)>=48 && str.charCodeAt(i)<=57) || (str.charCodeAt(i)>=97 && str.charCodeAt(i)<=122))
			{
					f=0;
					
			}
			else
			{
				f=1;
				break;
			}	
		}		
if(f==1)
  alert("Invalid");
else
  alert("Valid");
	
}
</script>
</head>
<body>
<form name=my id="my">
<table>
	<tr>
	<td><input type='text' name='first'></td><td></td>
	</tr>
	<tr>
	<td><input type='button' name='click' value='check ' onClick='check()'></td>
	</tr>
</table>

</body>
</html>

Also, you have to change statements in TRUE part of IF condition. What you have done is, you'll start checking each character. If it is valid, you will display a message and breaks the execution of the FOR loop. But that will prevent the code from checking other characters !

**Aash** · Jul 31st, 2011, 07:07 AM

yeah, u're right. I did it.

Code:

function check()
{
	var str=document.my.first.value;
		for(i=0; i<=str.length-1; i++)
		{
			if((str.charCodeAt(i)>=48 && str.charCodeAt(i)<=57) || (str.charCodeAt(i)>=97 && str.charCodeAt(i)<=122))
			{
					
			}
			else
			{
				alert("Invalid");
				break;
			}	
		}		
	
}

my stupid mistake

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