>perl -wMstrict -le "my @FMat; my @dipept = qw(xAAx yAAy xyzzy zAAzAAz zzzz); ;; $FMat[0][0] = grep(/AA/, @dipept); print qq{grepped: $FMat[0][0]}; ;; $FMat[0][0] = map /AA/g, @dipept; print qq{mapped: $FMat[0][0]}; ;; print qq{@dipept}; " grepped: 3 mapped: 4 xAAx yAAy xyzzy zAAzAAz zzzz