r - State name to abbreviation

Question

I have a large file with a variable state that has full state names. I would like to replace it with the state abbreviations (that is "NY" for "New York"). Is there an easy way to do this (apart from using several if-else commands)? May be using replace() statement?

Answer 1

R has two built-in constants that might help: state.abb with the abbreviations, and state.name with the full names. Here is a simple usage example:

> x <- c("New York", "Virginia")
> state.abb[match(x,state.name)]
[1] "NY" "VA"