How to rewrite this Stata code in R?

Question

One of the things Stata does well is the way it constructs new variables (see example below). How to do this in R?

foreach i in A B C D {  
    forval n=1990         


        

Answer 1

DONT do it in R. The reason its messy is because its UGLY code. Constructing lots of variables with programmatic names is a BAD THING. Names are names. They have no structure, so do not try to impose one on them. Decent programming languages have structures for this - rubbishy programming languages have tacked-on 'Macro' features and end up with this awful pattern of constructing variable names by pasting strings together. This is a practice from the 1970s that should have died out by now. Don't be a programming dinosaur.

For example, how do you know how many popXXXX variables you have? How do you know if you have a complete sequence of pop1990 to pop2000? What if you want to save the variables to a file to give to someone. Yuck, yuck yuck.

Use a data structure that the language gives you. In this case probably a list.