CODEWITHSUNDEEP
arraysperl
brucezepplin
brucezepplin

Reputation: 9752

Access and print nth element of sub array, for every array

I have a multidimensional array:

@multarray =  ( [ "one", "two", "three" ],
                [  4,   5,  6,  ],
                [ "alpha", "beta", "gamma" ]
              );

I can access @multarray[0]

[
    [0] [
        [0] "one"
        [1] "two"
        [2] "three"
    ]
]

or even @multarray[0][0]

"one"

But, how do I access say the 1st sub element of every sub array? Something akin to multarray[*][0] to produce:

"one"
4
"alpha"

Upvotes: 2

Views: 581

Answers (2)

toolic
toolic

Reputation: 62106

You can use map and dereference each array:

use warnings;
use strict;
use Data::Dumper;

my @multarray =  ( 
    [ "one", "two", "three" ],
    [  4,   5,  6,  ],
    [ "alpha", "beta", "gamma" ]
);

my @subs = map { $_->[0] } @multarray;
print Dumper(\@subs);

Output:

$VAR1 = [
          'one',
          4,
          'alpha'
        ];

See also: perldsc

Upvotes: 8

stevieb
stevieb

Reputation: 9296

Using a for() loop, you can loop over the outer array, and use any of the inner elements. In this example, I've set $elem_num to 0, which is the first element. For each loop over the outer array, we take each element (which is an array reference), then, using the $elem_num variable, we print out the contents of the inner array's first element:

my $elem_num = 0;

for my $elem (@multarray){
    print "$elem->[$elem_num]\n";
}

Upvotes: 3

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