The trailing at sign (@) enables the next INPUT statement to read from the current record in the same iteration of the DATA step. The double trailing at sign (@@) enables the next INPUT statement to read from the current record across further iterations of the DATA step. The term trailing indicates that the @ or @@ must be the last item specified in the INPUT statement, as shown in this example: input name $20. @; or input name $20. @@; It's easy to distinguish between @ and @@ by remembering that @ releases a record when control returns to the top of the DATA step @@ holds a record across iterations of the DATA step until the end of the record is reached.

Trailing At Sign (@)

Normally, each INPUT statement in a DATA step reads from a new record. But when you use the @, the following occurs: the input pointer remains at the same line, rather than moving down to the next record.

data perm.dataset; infile rawdata; input id 3. @; . . . input activity $;

1---V----10---+----20-- 001 WALKING AEROBICS  002 SWIMMING CYCLING 003 TENNIS SWIMMING

 

the next INPUT statement (in the same iteration of the DATA step) continues reading the same record, rather than the new one.

data perm.dataset; infile rawdata; input id 3. @; . . . input activity $;

1---+----10V--+----20-- 001 WALKING AEROBICS  002 SWIMMING CYCLING 003 TENNIS SWIMMING

data perm.dataset; infile rawdata; input id 3. @; . . . input activity $;

V---+----10---+----20-- 001 WALKING AEROBICS  002 SWIMMING CYCLING  003 TENNIS SWIMMING

     data perm.dataset;
        infile rawdata;
        input id 3. @;  
         .
         .
         .
     run;

     input id 4. @@;    
     .                    
     .                    
     input department 5.;