How to filter data without losing NA rows using dplyr

Question

How to subset data in R without losing NA rows?

The post above subsets using logical indexing. Is there a way to do it in dplyr?

Also,

Answer 1

The documentation for dplyr::filter says... "Unlike base subsetting, rows where the condition evaluates to NA are dropped."

NA != "str" evaluates to NA so is dropped by filter.

!grepl("str", NA) returns TRUE, so is kept.

If you want filter to keep NA, you could do filter(is.na(col)|col!="str")

Answer 2

If you want to keep NAs created by the filter condition you can simply turn the condition NAs into TRUEs using replace_na from tidyr.

a <- data.frame(col = c("hello", NA, "str"))
a %>% filter((col != "str") %>% replace_na(TRUE))