how to check null value

how to check null value

am 22.04.2008 10:09:19 von Irfan.Sayed

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Hi All,

=20

How to find out whether the string contains null values or empty data.

=20

For example : I have one scalar variable $str and now I want to check
whether it contains any data or not.

=20

What I did : If ($str eq "NULL" || $str eq " "){ print $str conatins
nothing\n";}

=20

Is this correct?? Because doing as per above code , I am not getting
proper result.

=20

Please help

=20

Regards,

Irfan

=20


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Re: how to check null value

am 22.04.2008 11:54:16 von igotux igotux

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perldoc -f defined should answer your question.

On Tue, Apr 22, 2008 at 1:39 PM, wrote:

> Hi All,
>
>
>
> How to find out whether the string contains null values or empty data.
>
>
>
> For example : I have one scalar variable $str and now I want to check
> whether it contains any data or not.
>
>
>
> What I did : If ($str eq "NULL" || $str eq " "){ print $str conatins
> nothing\n";}
>
>
>
> Is this correct?? Because doing as per above code , I am not getting
> proper result.
>
>
>
> Please help
>
>
>
> Regards,
>
> Irfan
>
>
>
>

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Re: how to check null value

am 22.04.2008 12:02:02 von Lars Haugseth

* Irfan.Sayed@t-systems.com wrote:
>
> How to find out whether the string contains null values or empty data.
>
> For example : I have one scalar variable $str and now I want to check
> whether it contains any data or not.
>
> What I did : If ($str eq "NULL" || $str eq " "){ print $str conatins
> nothing\n";}

Try this:

if (!defined $str || $str eq "") { ... }

Almost but not quite the same:

if (!$str) { ... }

Here the block will also be executed if the value of $str is 0.

--
Lars Haugseth

"If anyone disagrees with anything I say, I am quite prepared not only to
retract it, but also to deny under oath that I ever said it." -Tom Lehrer

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