Conditional copy value

[lpy0521]

Hi, there

my data looks like this:
ID   var1  var2
111 aaa   100
111 aaa   101
111          102

111          
222 bbb  101
222 bbb  102
222         103

Just curious how can I fill the null var1 with previous row's value ony if var2 is not null and the desired data looks like:  

want 
ID   var1 var2
111 aaa  100
111 aaa  101
111 aaa  102

111
222 bbb  101
222 bbb  102
222 bbb  102

Thanks in advance!

[novinosrin]

data have;
input ID   var1 $ var2 ;
cards;
111 aaa   100
111 aaa   101
111   .       102
111    .       .
222 bbb  101
222 bbb  102
222    .     103
;

data want;
set have;
by id;
k=lag(var1);
if not first.id and missing(var1) and k>' ' and var2 then var1=k;
drop k;
run;

[Ksharp]

data have;
input ID   var1 $ var2 ;
cards;
111 aaa   100
111 aaa   101
111   .       102
111    .       .
222 bbb  101
222 bbb  102
222    .     103
;

data want;
 set have;
 length new_var1 $ 80;
 retain new_var1 new_var2;
 by id;
 if first.id then call missing(new_var1,new_var2);
 if not missing(var1) then new_var1=var1;
 if not missing(var2) then new_var2=var2;
 if cmiss(new_var1,new_var2)=2 then call missing(new_var1,new_var2);
run;

[mkeintz]

What if you have consecutive instances of missing var1  but non-missing var2?   I.e. what if you have

data have;
input ID   var1 $ var2 ;
cards;
111 aaa   100
111 aaa   101
111   .       102
111   .       103
111    .       .
222 bbb  101
222 bbb  102
222    .     103
;

[lpy0521]

I will only copy var1 when var 2 is not missing. missing var 1 is not irrelevant in this case, thanks!

[Allaluiah]

What have you tried? Can you show your sincere attempt? I have noticed you haven't showed either in any of your threads and I think that's unfair

[ShiroAmada]

Try this.

data want;
 set sample;
var1=ifc ((var1="" and var2>0),lag(var1),var1);
run;