One way is to use List::MoreUtils:

use warnings;
use strict;
use List::MoreUtils qw(firstidx);

my @array = (2,4,7,5,8); 
printf "item with index %i in list is 7\n", firstidx { $_ == 7 } @arra
+y;

__END__

item with index 2 in list is 7
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