09-08-2017 12:11 PM
The : is used to indicate that the format reading the data starts reading at the next non-blank column until it reaches a blank column in the data. If the : then a format may force reading more characters than you intend when the length of values vary. Note the value of x in the first data set and the error message in the first example step below. Then the behavior with the :
data example; input x $10. y; datalines; short 23 longer 19 ; run; data example2; input x : $10. y; datalines; short 23 longer 19 ; run;
The @ holds the input pointer on the same line. One use is conditionally read data depending on the values of something read before the @ sign.