HNSKD questions

• Combining columns, while ignoring duplicates and NAs
• How do I impute missing variables in R using dplyr?
• R: How do you apply grep() in lapply()
• Calculating age using mutate with lubridate functions [duplicate]
• How can we check if any 2 intervals of a unique ID overlaps?
• How to filter rows based on difference in dates between rows in R?

HNSKD answers