The while command processes commands while an initial expression is true. To make sure an infinite loop isn't created the while command needs to have the initial expression that is running the loop change at some point inside the loop so that it eventually is no longer true. These ideas are shown in examples that follow. After looking at the examples read this again and hopefully it will make more sense. The while command is very useful, but the for command usually requires less typing.
Some users simply prefer the while command to the for command.
Click here to see webpages about variable labels and value labels . Users generally use local macro variables because they are not associated to the data set. Send them to Phil Bardsley.