Sum of several variables calculated into one newly created variable...

[Dalila Ahamed]

I have used SPSS in the past, and new to STATA . No statistical background per se, but a social researcher.
Need some help on how to create a new variable that calculates automatically the sum of several variables put together.

i have asked interviewees which month of the year they worked in the field - so, in Stata; for each month ( january to December), i have a variable - and 0 for not worked , 1 for worked.
I want now to calculate how many months in the year they worked, which logically should be the sum of all months put together. so sum ( var1+var2+...)
However , when computing this command, i obtain results that dont look like what i expected.

Any advice on how to do this ( in lay language please)?

Thanks

[Maarten Buis]

gen monthsworked = var1 + var2 + var3 + ...

or

egen monthsworked = rowtotal(var1 var2 var3 var4 ...)

[Dalila Ahamed]

Great! Thank you .... it worked perfect!

[Nick Cox]

It is hard to see what you did but note that the function sum() gives you a cumulative or running sum combining results across different observations. For sums within the same observations it will give incorrect results almost everywhere.