Dynamic variable names in SAS

Question

Is there a way in SAS to specify dynamic variable names in code? i.e. use different variables on different observations based on the value of another variable?

For

Answer 1

If you create an array of Var1 - VarN then you can easily reference the value stored in Index.

data have;
input Index  Var1   Var2  Var3;
cards;
1      78.3   54.7  79.8
3      67.2   56.2  12.3
2      65.3   45.2  98.1
1      56.2   49.7  11.3
1      67.2   98.2  98.6
;
run;

data want;
set have;
array vars(*) var: ;
var_index=vars(index);
run;

Answer 2

data want;
    set have;
    length _var_name $32 _var_num 5;
    array vars(*) var: ;
    /* if you want name of variable */
    _var_name=VNAME(vars(index));
    /* if you want numeric suffix of variable 
            and suffix is not same as position of variable in array
          (so that vars(index) is not usable */
    _var_num=INPUT(SUBSTR(_var_name, ANYDIGIT(_var_name)),32.);
run;

So what you need is VNAME() function.

Answer 3

Wouldn't a data step work?

 data assign_value;
  set have;

  if index = 1 then var_index = var1;
  else if index = 2 then var_index = var2;
  else if index = 3 then var_index = var3;
run;

I might be missing something? but this should give you the result from your question.

Answer 4

I think the simplest solution would be to use VVALUEX function. It creates the variable name using the index, and then supplies it as an argument to the function -

var_index = vvaluex(compress("var" || put(index, 8.)));