Conditional mutating with dplyr for only some rows

Question

I use ifelse with mutate to conditionally change variable names within a column. For example:

mutate(df, thiscol = ifelse((new == "oldname"), "newname", NA)

But I would like to change it so that instead of variables that don't fit the conditions turning into NA, they just stay as they were.

Answer 1

mutate(df, thiscol = ifelse(new == "oldname", "newname", thiscol))

Answer 2

If we need to change only some elements and keep the rest as the same, then another option is replace

df %>%
    mutate(thiscol = replace(thiscol, new == "oldname", "newname"))