How does SAS handle missing values in a SUM function?

In SAS, when using the SUM function, missing values are effectively ignored during the calculation. This means that only the non-missing values are considered when computing the total sum. If there are multiple missing values in the dataset, these do not contribute to the sum and do not alter the outcome of the function.

For instance, if you have a dataset that includes the values 3, ., 5, and 7 (where the dot represents a missing value), when you apply the SUM function, SAS will add only the numbers 3, 5, and 7, resulting in a total of 15, while the missing value is disregarded.

This behavior allows analysts to compute sums without the need to manually handle missing data, facilitating smoother data analysis and reporting in SAS programs.