data army navy airforce marines; 
   drop Type; 
   set prog2.military;    
   if Type eq 'Army' then
      output army;
   else if Type eq 'Naval' then 
        output navy;
   else if Type eq 'Air Force' then
        output airforce;
   else if Type eq 'Marine' then
        output marines;     
run;

data army(drop=City State Country Type)
     navy(drop=Type) 
     airforce(drop=Code Type) 
     marines;                                                                                                        
   set prog2.military;    
   if Type eq 'Army' then
      output army;
   else if Type eq 'Naval' then 
        output navy;
   else if Type eq 'Air Force' then
        output airforce;
   else if Type eq 'Marine' then
        output marines;     
run;

data army(keep=Code Airport)
     navy(keep=Code Airport City State Country)
     airforce(keep=Airport City State Country) 
     marines;                                                                                                        
   set prog2.military;    
   if Type eq 'Army' then
      output army;
   else if Type eq 'Naval' then 
        output navy;
   else if Type eq 'Air Force' then
        output airforce;
   else if Type eq 'Marine' then
        output marines;     
run;

data army(keep=Code Airport);
   set prog2.military(drop=City State Country);
   if Type eq 'Army' then output;
run;

data army;
   set prog2.military(firstobs=11 obs=25);
   if Type eq 'Army' then 
      output;
run;