Keep vs Retain Statement

[DMMD]

Could someone tell me the difference between Keep and Retain statements for SAS?

Thanks!

[chrej5am]

keeps refers to the variable beeing read or written in the dataset

retain stores the value of a variable between observations, it surpresses reseting of the variable

[ballardw]

In addition ot @chrej5am, Keep (and Drop) can be a data set option and used anywhere a dataset is used to restrict the variables used by a procedure. Retain is only valid in a data step.

[Kurt_Bremser]

Adding to what @chrej5am said, retain works reliably only with newly created variables. Variables that are already present in the input dataset(s) will be overwritten anytime a new observation is read.