THE SPECIAL “??” FORMAT MODIFIER

The following excerpt is from SAS OnlineDoc documentation:

? or ??

Direct link: http://www.nesug.org/Proceedings/nesug01/at/at1013.pdf

The optional question mark (?) and double question mark (??) format modifiers suppress the printing of both the error messages and the input lines when invalid data values are read. The ? modifier suppresses the invalid data message. The ?? modifier also suppresses the invalid data message and, in addition, prevents the automatic variable _ERROR_ from being set to 1 when invalid data are read.

Below is an example of using ?? to determine whether a variable contains non-numeric values or not:

data _null_;
x = “12345678”;
if (input(x, ?? 8.) eq .) then
put ‘non-numeric’;
else put ‘numeric’;
run;

Running SAS would return “Numeric” in the above example. If we used X=”123a5678”, SAS would return “Non-Numeric”. Note that the input format in the above example is “8.” So only the first 8 bytes of the character string are checked.

Thus, X=123456789a would return “Numeric” as it would only be checking the first 8 bytes of the string.

 

 

I found an  interesting tip about suppressing the invalid data note and/or error message when reading in formatted data while surfing on the net.... (Source : Queensland Users Exploring SAS Technology)

 

Tips & Techniques - #3

Q: Is there a way to suppress the invalid data note and/or error message when reading in formatted data?

A:

􀂄Use the Format Modifiers ? or ?? on the input statement (or input function)

􀂄? –suppresses printing the invalid data note when SAS encounters invalid data values.

􀂄??––suppresses printing the messages and the input lines when SAS encounters invalid data values. The automatic variable _ERROR_ is not set to 1 for the invalid observation.

􀂄For example:

input x ?? 10 10-12;


Is the same as:


input x ? 10 10-12;


_error_=0;