jscript, checking to make sure that an input is a number

Gonzose
#1 / 8

checking to make sure that an input is a number

I need to know how to check if an input is a number.
Help.
Not just an integer but a positive number

Sun, 15 May 2005 02:50:49 GMT

rayda
#2 / 8

checking to make sure that an input is a number

Try regular expressions.
This one:
^[+]?\d+(\.\d+)?$
was taken from the site:
http://regexlib.com/REDetails.aspx?regexp_id=117
You can go to the site and test it to see if it suits your needs.

Quote:

> I need to know how to check if an input is a number.
> Help.
> Not just an integer but a positive number

Sun, 15 May 2005 02:53:52 GMT

rayda
#3 / 8

checking to make sure that an input is a number

Oops,
Sorry, the expression I gave you
^[+]?\d+(\.\d+)?$
matches positive number while the one on the site
^[-+]?\d+(\.\d+)?$
matches positive and negative numbers.

Sun, 15 May 2005 03:01:40 GMT

Gonzose
#4 / 8

checking to make sure that an input is a number

That works except if I have .125 this returns false...

Quote:

> Try regular expressions.
> This one:
> ^[+]?\d+(\.\d+)?$
> was taken from the site:
> http://regexlib.com/REDetails.aspx?regexp_id=117
> You can go to the site and test it to see if it suits your needs.

> > I need to know how to check if an input is a number.
> > Help.
> > Not just an integer but a positive number

Sun, 15 May 2005 03:11:24 GMT

rayda
#5 / 8

checking to make sure that an input is a number

Try this:
^[+]?(\d+)?(\.)?(\d+)?$

Quote:

> That works except if I have .125 this returns false...

> > Try regular expressions.
> > This one:
> > ^[+]?\d+(\.\d+)?$
> > was taken from the site:
> > http://regexlib.com/REDetails.aspx?regexp_id=117
> > You can go to the site and test it to see if it suits your needs.

> > > I need to know how to check if an input is a number.
> > > Help.
> > > Not just an integer but a positive number

Sun, 15 May 2005 03:40:30 GMT

Gonzose
#6 / 8

checking to make sure that an input is a number

OK Now I am really going to show how little i know about jscript
How do I use this.
I have the value f.size.value

Quote:

> Try this:
> ^[+]?(\d+)?(\.)?(\d+)?$

> > That works except if I have .125 this returns false...

> > > Try regular expressions.
> > > This one:
> > > ^[+]?\d+(\.\d+)?$
> > > was taken from the site:
> > > http://regexlib.com/REDetails.aspx?regexp_id=117
> > > You can go to the site and test it to see if it suits your needs.

> > > > I need to know how to check if an input is a number.
> > > > Help.
> > > > Not just an integer but a positive number

Sun, 15 May 2005 04:39:46 GMT

rayda
#7 / 8

checking to make sure that an input is a number

Untested.
Look into RegExp for more information.
Sorry, I mostly use regular expressions testing in ASP and the expression I
gave you earlier was in ASP.

function only_digit(src)
{
if (src.value.match(^[\d+]?[\.]?[\d+]?$))
{
alert("Numeric only");
return false;
}

return true;

Quote:

}

Quote:

> OK Now I am really going to show how little i know about jscript
> How do I use this.
> I have the value f.size.value

> > Try this:
> > ^[+]?(\d+)?(\.)?(\d+)?$

> > > That works except if I have .125 this returns false...

> > > > Try regular expressions.
> > > > This one:
> > > > ^[+]?\d+(\.\d+)?$
> > > > was taken from the site:
> > > > http://regexlib.com/REDetails.aspx?regexp_id=117
> > > > You can go to the site and test it to see if it suits your needs.

> > > > > I need to know how to check if an input is a number.
> > > > > Help.
> > > > > Not just an integer but a positive number

Sun, 15 May 2005 05:47:08 GMT

Dr John Stockto
#8 / 8

checking to make sure that an input is a number

Tue, 26 Nov 2002 13:50:49 :-

Quote:

>I need to know how to check if an input is a number.
>Help.
>Not just an integer but a positive number

You probably do not need to know that. For example, "positive number"
includes 3.14159E0 and 5E+300 - do you need to accept those?

If what you are doing is in essence inputting a count, then you can call
and test for a number of 1 to N decimal digits, using a RegExp such as
/\d{1,8}/.

For the case of non-integer, you should require at least one digit on
each side of the decimal point; and you should perhaps require the
decimal point. Allowing numbers to have a decimal point at one end
becomes error-prone.
If the input is a currency, you should probably not allow just a single
digit after a decimal point; that is liable to be an error.

Beware of allowing an empty string, unless specified permissible.

--

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Sun, 15 May 2005 22:06:37 GMT