General form, SORT procedure: PROC SORT <option(s)>; BY <DESCENDING> variable-1      <...<DESCENDING> variable-n>; where option(s) includes the DATA= and OUT= data set options.

PROC SORT rearranges the observations in a data set according to the values of the variables in the BY statement. Multiple sort variables may be used.

Specifying Output
	Specifying an output data set can be crucial when using PROC SORT. By default, the SORT procedure overwrites the current data set with newly sorted observations. To preserve your original data, include the OUT= option and specify an output data set. Then use the DATA= option in later programming steps to read the sorted observations.

For example, the SORT procedure shown below sorts the observations of the data set Finance.Credit by the values of the variable Account. Because Finance.Credit is overwritten, its orginal order is lost.

SAS Data Set Finance.Credit (before SORT)

proc sort data=finance.credit; by account; run;

SAS Data Set Finance.Credit (after SORT)

Including the OUT= option preserves your original data. In this case, the sorted version of Finance.Credit is the newly created data set Work.Credsort. proc sort data=finance.credit out=work.credsort; by account; run;

Specifying Sort Order The default SORT procedure order is ascending, but can be reversed by including the DESCENDING keyword before any variable in the BY statement. proc sort data=finance.credit out=work.credsort; by descending account; run;

SAS Data Set Work.Credsort