Re^2: perl array of hashes help

[Anonymous Monk]

in reply to Re: perl array of hashes help
in thread perl array of hashes help

Hi Trizen, Thanks for your help , the code is working fine, can you please explain the two codes, similar to first one when i tried like this grep { $_->{bill} =~ '1117'} @array dint worked.. so what does ~~ this mean could you please explain me clearly. regards Sridhar

[trizen]

Hi Sridhar! Please take a look at the smart match operator. As you can see, 'item' ~~ \@array returns true if the 'item' exists inside the array passed as an array reference.

Your code doesn't work because $_->{bill} is a reference to an array, so what you are actually trying is something like this: 'ARRAY(0x886b7f8)' =~ /1117/; (i.e.: return true if the left side contains the substring from the right side).

Of course, if you're trying to match a substring inside an array, you can use: grep { qr/1117/ ~~ $_->{bill} } @array;

[ragilla]

Hi Trizen,

I have one question regarding access of the perl hash key which is an array reference like below i have an hash

 my $all = {'text' => [                                      'HJ0039_x.pdf' , 'HJ0039' , 'HJ0039'                                      ]};

To access the above elements i can use two ways like below

 print " $all->{text}[0] ;

and

 print "${$all->{text}}[0]

can you please explain me clearly what is the difference between the above two methods , without de-referencing the array how we are able to access the array elements

Thanks

[trizen]

Hello Ragilla,

The code $all->{text}[0] is equivalent with $all->{text}->[0]. This implies an implicit dereference. Similar with $array_ref->[0].

In the second code, ${$all->{text}}[0] is similar with $array[0], because $all->{text} is an ARRAY REF, and @{ARRAY_REF} is similar with @array, which can lead to ${ARRAY_REF}[index].