Coalesce two string columns with alternating missing values to one
You may try pmax df$c <- pmax(df$a, df$b) df # a b c # 1 dog <NA> dog # 2 mouse <NA> mouse # 3 <NA> cat cat # 4 bird <NA> bird …or ifelse: df$c <- ifelse(is.na(df$a), df$b, df$a) For more general solutions in cases with more than two columns, you find several ways … Read more