Initialization of PDV
Once the PDV is established, certain values are assigned to the variables.
The variables created by the INPUT statement, such as NAME and AGE in our example, are initialized with a missing value.
For character variables, it is a blank. For numeric variables, it is a period.
The automatic variable _n_ is initialized with the numeric value 1.
This indicates the first iteration of the execution phase.
You will learn more about data step iteration in the next few sections.
The _error_ variable is assigned the value 0. This indicates no error in this particular record.
When SAS encounters an error in a particular record, the _error_ variable will change to 1.
An example will again be demonstrated shortly.
