Variables that are null or contain no data. 1

[timgerr]

I am trying to see if a variable has any data in it, how can I see if a variable is null or does not contain any data.

Thank you,

Tim Gallagher


-How important does a person have to be before they are considered assissinated instead of just murdered?

 

[waiterm]

you can use the 'eq' sign to compare variables and their contents, for example:

if ($variable eq "")  {
    print "Variable is empty\n";
}  else  {
    print "Variable is not empty\n";
}

It looks like you're maybe a newbie so a good resource for perl can be found here:

http://docs.rinet.ru/P7/

Rob Waite

http://www.hostpipe.co.uk?src=TT

 

[waiterm]

Forgot to add, use '==' and '!=' when comparing numbers, 'eq' and 'ne' when comparing strings, and '=' when setting variables.

Rob Waite

http://www.hostpipe.co.uk?src=TT

 

[timgerr]

Thanks, I am a newbie to perl, comming from a VB/WMI background.

Timgerr

-How important does a person have to be before they are considered assissinated instead of just murdered?

 

[ishnid]

If you want to check if a variable is defined, use the aptly-named defined function:

if (defined $variable && $variable ne "") {
   #variable is defined and not empty
}
else {
   #variable is undefined or empty
}

waiterm's code will throw a warning if $variable is undefined.

 

[MikeLacey]

If you're lazy - you can just type

if($variable){
print "is defined and has a value\n";
} else {
print "is undefined or has no value\n";
}


Mike

"Deliver me from that bane of civilised life; teddy bear envy."

Want to get great answers to your Tek-Tips questions? Have a look at faq219-2884

 

[philote]

Mike, if $variable has a value of zero, wouldn't that also print "is undefined or has no value"?

 

[MikeLacey]

It might do...

Mike

"Deliver me from that bane of civilised life; teddy bear envy."

Want to get great answers to your Tek-Tips questions? Have a look at faq219-2884