Create a table using values from macro variables

[ayin]

Users define a couple of macro variables (input):

%let category = A B;
%let class = apple banana;
%let column = index character;

The generated table/dataset (output) would look like:

category class index character
   A     apple   .       .
   A     banana  .       .
   B     apple   .       .
   B     banana  .       .

As you can see, for column 1 and column 2, they basically go through values of the macro variables, with macro variables' names as the column names. For column 3 and column 4, blanks, with macro variable's value as the column names (column 'index' has numeric values; column 'character' has char.)

How to achieve it?

[Astounding · Accepted solution]

Untested, so it's possible it needs a little debugging:

%macro generate (category=, class=, column=);

%local i j;

data want;

length category class $ 8 &column 8;

%do i=1 %to %sysfunc(countw(&category));

%do j=1 %to %sysfunc(countw(&class));

category = "%scan(&category, &i)";

class = "%scan(&class, &j)";

output;

%end;

%end;

run;

%mend generate;

%generate (category=A B, class=apple banana, column=index character)