How to skip a paste() argument when its value is NA in R

Question

I have a data frame with the columns city, state, and country. I want to create a string that concatenates: \"City, State, Country\". However, one of my cities does

Answer 1

The alternative is to just fix it up afterwards:

gsub("NA, ","",dff$string)

#[1] "Austin, Texas, United States"       
#[2] "Knoxville, Tennessee, United States"
#[3] "Salk Lake City, Utah, United States"
#[4] "Prague, Czech Rep"   

Alternative #2, is to use apply once you have your data.frame called dff:

apply(dff, 1, function(x) paste(na.omit(x),collapse=", ") )