Image result for if and where statement in sas
The WHERE statement is more efficient than IF statement. It tells SAS not to read all observations from the data set. Look at the LOG after using WHERE statement, you only see a count of the number of observations that meet the criteria in the WHERE statement.
For knowing in details about SAS you can enroll in the<a href="http://pythonandmltrainingcourses.com/courses/best-sas-training-in-delhi/">Best SAS Course in Delhi/a> which provides full live projects facilities and also provides online classes.
