Trouble using the minus sign for counting down a variable

[TurnTheBacon]

This is an embarrasing question, but what exactly is wrong with using the minus sign to count down a variable, such as inside this do-while loop?

data work.countdown;

count = -1;

do while (count NE -100);

       count -1;

end;

run;

proc print data=work.countdown;

run;

It runs perfectly with a plus sign, but once I use the minus sign the count variable turns red and I get this message in the log: "ERROR 180-322: Statement is not valid or it is used out of proper order."

[Quentin · Accepted solution]

Hi,

The count+1 thing is it's own type of statement, it's a SUM STATEMENT.  It needs to be a plus sign.  There is no equivalent DECREMENT statement.

If you want to do the same (set to 0, retain, use sum function) but decrement, you can do:

count + - 1;

or

count + (-1);

HTH,

--Q.

[TurnTheBacon]

Thanks, that answers my question very well.