/*****************************************************************************************************************

SAS file name: Replace_Missing_Zero.sas
File location: 
_________________________________________________________________________________________________________________

Purpose: To Demonstrate how to replace missing values woth zeros for specific and all numeric variables 
         in a SAS data set using the Data Step and PROC STDIZE
Author: Peter Clemmensen
Creation Date: 15/11/2016

This program supports the blog post "Replace Missing Values with zero in SAS" on SASnrd.com

*****************************************************************************************************************/

/* Example Data */
data Missing_Values;
input ID$ var1 var2 var3;
datalines;
1 . 3 4 
2 2 0 .
3 . . 3
4 . 8 .
5 5 . .
;

/* Replace Missing Values with Zero With the Data Step */
data DataStepMethod;
   set Missing_Values;
   array NumVar _numeric_;
   do over NumVar;
      if NumVar=. then NumVar=0;
   end;
run;

/* Replace Missing Values of all numeric variables with Zero With PROC STDIZE */
proc stdize data=Missing_Values out=StdizeMethod_All reponly missing=0;
run;

/* Replace  Missing Values of only the specified variables */
proc stdize data=Missing_Values out=StdizeMethod_Var reponly missing=0;
   var var1;
run;