Perl Data Structures: How to create an array ref from an array

Question

I have the following data structure:

@keys = [1, 2, 3, 4];

And using a loop (for) from 1 to 4, I want to create a new data structure like

$new = +{ key => '1',
 meaning => '',
 time => '', };

So, basically I would have in this case four $new data structures.

Do I need to use the map function?

• mpapec: You can use map or foreach although map is more common/idiomatic.
• TLP: @keys = [1, 2, 3, 4] does not assign an array, it assigns an array of arrays (well, the first element of the array is an array).
• TLP: @mpapec Rolled back your edit. You cannot fix code in the question unless the OP clearly says it was a typo.
• ado: yes im terribly sorry, i meant @keys = (1, 2, 3, 4)

Answer 1

Confusing question, but I think you problem is that

@keys = [1, 2, 3, 4];

is probable not what you mean. It should be either

@keys = (1, 2, 3, 4);

or

$keysref = [1, 2, 3, 4];

I'll assume the first. Then yes, you could populate an array of records with map

@records = map( {key => $_,meaning => '',time => ''}, @keys );

Answer 2

my @keys = (1, 2, 3, 4);
my @array = map +{ 
 key => $_,
 meaning => '',
 time => '', 
} @keys;

now @array has same number of elements as @keys and they are hash references.

• TLP: Your edit on the main question is questionable. If the OP really has that in his own code, then it will be impossible for anyone to help him.
• mpapec: my guess was that OP did typo.
• TLP: Yes, why else would you have done it. Still, it is possible it is not a typo.