multiplying a variable for -1

[ari2495]

HI, i'm trying to understand a code, i found the following:

data Db_1;
set db;
variable= variable*(-1) ;
run;

what could be the reason? i can't understand this data step

[PaigeMiller]

You could actually try running the code and seeing what happens with your own eyes, does the value of VARIABLE change? What does it change to?

But let me ask another question — forget SAS for a moment, just answer based upon what you have learned about math in your life — what do you get if you multiply a number, let's say the number 5, by -1 ? Do this in your head or on paper, what do you get?