find a row with a column value don't remove duplicated cells

i compare data in two sheets, if there are a dublicated row i want to save its last cell column in the previous row i use for i=1:size(alldata,1) for j=1:length(defs)

        if data2{j,1}==alldata{i,1}                 % compare MDR in two files, if equal

            data1(j,:)=alldata(i,:);          % put all data of text in array(data1)

        if data1{j-1,1} == data1{j,1}        % here it gives me error

            data1(j,C2+1)=alldata(i,6);        % put dyplicated text in C7  works good
        end
        end
    end
end

but it gives me error in

" if data1{j-1,1} == data1{j,1}"

how i can solve this ?

Answer 1

[Nobel Mondal]

for j=1, it is trying to access data1{0,1} but matlab indexing starts from 1.

[Amr Hashem]

how i can solve this?

i want to compare the new result with the previous one