Retain statement

[Jianan_luna]

When I was doing the practice question from Programming 2 lesson 2. The question indicate to initialize trafficmax to 0. I did that, but from the answer, the retain statement is:retain traffixmax 0 MonthMax LocationMax. I am confused that add monthmax and locationmax on the end of statement. And what does that stand for? Thanks!

[ChrisNZ]

It means that  monthmax & locationmax   are retained too, but with no initial value (i.e. set to missing).