"Perl for Perl Newbies" - Part 2ReferencesThe Arrow Operators

10.5. The Arrow Operators

An arrow ( ->) followed by a square or curly brackets can be used to directly access the elements of an array or a hash referenced by a certain hash. For instance: $array_ref->[5]will retrieve the 5th element of the array pointed to by $array_ref.

As an example let's print a tree of the contents of the part of the lecture that was presented in the previous slide:

use strict;
use warnings;

do
"lol.pl";
# Load the other file

my
$cont = get_contents();

print
$cont->{
'title'
},
"
\n
";
print
$cont->{
'subs'
}->[
0
]->{
'url'
},
"
\n
";
print
$cont->{
'subs'
}->[
0
]->{
'subs'
}->[
1
]->{
'title'
},
"
\n
";

Note that the arrows following the first arrow are optional as perl sees that the programmer wishes to access the subseqeunt sub-items. However, the first one is mandatory because the expression $array_ref{'elem'}looks for the hash %array_ref.


Written by Shlomi Fish