@array = map { exists $_->{mykey} ? $_->{mykey} : () } @array;

[download]
Update: this also checks for existence of the key, if you don't need to, go for Abigail's solution. 
-- 
Joost       downtime n. The period during which a system
            is error-free and immune from user input.

[download]

In reply to Re: Play golf on an array of hashrefs by Joost
in thread Play golf on an array of hashrefs by very empty

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