Find whether an element exists in an array.

Sherlock · 06-20-2007, 11:15 AM

i have an array ..

@group =qw(AA BA CA);

I want to find whether an element i give ....exists in the array..

$val ="AA";

i tried exists ..its a soalris os

it says...exists argument is not a HASH type...

What is the solution for this???

Regards

Sherlock · 06-20-2007, 11:35 AM

Quote:

Originally Posted by Sherlock

i have an array ..

@group =qw(AA BA CA);

I want to find whether an element i give ....exists in the array..

$val ="AA";

i tried exists ..its a soalris os

it says...exists argument is not a HASH type...

What is the solution for this???

Regards

The exact error is

exists operator argument is not a HASH element

wjevans_7d1@yahoo.co · 06-20-2007, 11:49 AM

Two questions:

What language are you using?

Can you post a tiny but complete script which demonstrates the problem?

Sherlock · 06-20-2007, 11:42 PM

Quote:

Originally Posted by wjevans_7d1@yahoo.co

Two questions:

What language are you using?

Can you post a tiny but complete script which demonstrates the problem?

i am using Perl 5.005 on solaris

@group =qw(AA BA CA);

$val="AA";

exists($group[$val]));

I get the below error ....on running the program
exists operator argument is not a HASH element

paulsm4 · 06-20-2007, 11:57 PM

Hi -

I think you might be confusing Perl "arrays" with "hashes".

You can use "exists" with a hash, but not an array.

To see if a given value exists in an array...
then you simply need to iterate through the array...
either until you find an instance of that value (there might be many)...
or until you reach the end of the array (in which case the value does *not* exist in the array).

'Hope that helps .. PSM

Sherlock · 06-21-2007, 12:39 AM

Quote:

Originally Posted by paulsm4

Hi -

I think you might be confusing Perl "arrays" with "hashes".

You can use "exists" with a hash, but not an array.

To see if a given value exists in an array...
then you simply need to iterate through the array...
either until you find an instance of that value (there might be many)...
or until you reach the end of the array (in which case the value does *not* exist in the array).

'Hope that helps .. PSM

Thanks Paul...But hw can i modify the same array into a hash??

chrism01 · 06-21-2007, 01:55 AM

you could use Perl's internal grep http://perldoc.perl.org/functions/grep.html on the array, or you can create a hash

Code:

%group = ( AA => 1,
           BA => 1,
           CA => 1
         );

I'm assuming this is just an exercise, hard-coding values like that is rare in prodn code.
Also, FYI, RH8 is waaaay old and unsupported, as is Perl 5.0.
Strongly advise you to move up to a modern distro eg the RH replacement distro Fedora core, which is now at v7(!)
Perl is now at 5.8 (per my link to the grep fn)

bigearsbilly · 06-21-2007, 02:07 AM

grep /value/, @array

Code:

#!/usr/bin/perl -w

use Env;
@P = split ':', $LD_LIBRARY_PATH;

print grep /dt/, @P;
print "\n";

run it

Code:

dysp0024:primalA$ ./1.pl
/usr/dt/lib

Sherlock · 06-21-2007, 07:07 AM

Quote:

Originally Posted by bigearsbilly

grep /value/, @array

Code:

#!/usr/bin/perl -w

use Env;
@P = split ':', $LD_LIBRARY_PATH;

print grep /dt/, @P;
print "\n";

run it

Code:

dysp0024:primalA$ ./1.pl
/usr/dt/lib

Ok I will try the same ....

Thanks All