Function to return valid percentage?

MrPeds · Oct 31, 2006

Hi.

I am a bit of a newbie to JavaScript, so apologies in advance.

I am trying to validate a textbox to see if the value that is typed is of the following format:

23%

or

23

Basically, i am looking to return true or false if the numeric part is less than or equal to 100, and if the % sign is not present on the rhs simply validate that the number is a number.

I was thinking of using a regular expression, but could this be overkill?

Any suggestions are appreciated.

Regards.

MrPeds

kaht · Oct 31, 2006

regular expressions are NEVER overkill [wink]

Code:

<html>
<head>
<script type="text/javascript">

function blah(str) {
   if (/^(\d{1,2}|100)\%?$/.test(str)) {
      alert("passed validation");
   }
   else {
      alert("failed validation");
   }
}

</script>
</head>

<body>

<input type="text" id="txt" />
<input type="button" value="test if number" onclick="blah(document.getElementById('txt').value)" />
</body>
</html>

-kaht

http://www.silkypups.com

[small](All puppies have now found loving homes, thanks for all who showed interest)[/small]

trollacious · Oct 31, 2006

From a high priest of Regular Expressions: kaht.

#

You could also use the method parseFloat(str, 10) to check the string. parseFloat will allow decimal places in the percentage where parseInt will only return a whole number.

Lee

BillyRayPreachersSon · Oct 31, 2006

Basically, i am looking to return true or false if the numeric part is less than or equal to 100

If you want to return true or false, you don't even need a test. Presumably, you only want to return true?

Dan

Coedit Limited - Delivering standards compliant, accessible web solutions

[tt]Dan's Page [blue]@[/blue] Code Couch

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MrPeds · Nov 7, 2006

Indeed, the function should probably only return true.

e.g. if(!fnValid() ){ }

Thanks for your help.

MrPeds

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Function to return valid percentage?

MrPeds

Programmer

kaht

Programmer

trollacious

Programmer

BillyRayPreachersSon

Programmer

MrPeds

Programmer

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