scoring responses

[dustychair]

Hi all,

I have a data set including student's responses and missing values. I use the code below to score those responses. However, this code changes missing values to zeros as well. I want to change only responses and leave missing values as they are. Could you help me to edit this code. 

Thank you

data d912_binary (keep=id item: );
set d912;
if _n_ = 1 then set key;
array it {*} it1-it108;
array k {*} k1-k108;
array item {*} item1-item108;
do i = 1 to 108;
item{i} = (k{i} = it{i});
end;
run;

[dustychair]

I think I succeed. Here is what I did.

data d912_binary (keep=id item:);
set d912;
if _n_ = 1 then set key;
array it {*} it1-it108;
array k {*} k1-k108;
array item {*} item1-item108;
do i = 1 to 108;
if it{i} ne '.' then item{i} =(k{i} = it{i}) ; else item{i}=it{i};
end;
run;