R String Concatenation
R gives you several ways to join strings together, from the simple paste() function to the collapse-friendly tools built on top of it.
Why You Can't Just Use +
R does not overload the + operator for text the way some languages do — arithmetic operators only work on numbers. Instead, you combine strings with paste(), which glues its arguments together and inserts a single space between them by default. You can change that gap with the sep argument, or remove it entirely.
Example
first_name <- "Ada"
last_name <- "Lovelace"
paste(first_name, last_name)
# "Ada Lovelace"
paste("2026", "07", "17", sep = "-")
# "2026-07-17"The Shortcut: paste0()
Setting sep = "" is so common that R gives it its own function: paste0(). paste0(a, b) behaves exactly like paste(a, b, sep = ""), making it the idiomatic choice whenever you want text stuck together with no gap at all.
Example
item <- "apple"
count <- 3
message <- paste0("You have ", count, " ", item, "s")
print(message)
# "You have 3 apples"
filename <- paste0("report_", 2026, ".csv")
# "report_2026.csv"Concatenating Whole Vectors
paste() is vectorized, so when you hand it vectors of the same length it pairs elements up position by position instead of looping manually. Add the collapse argument when you want the whole result flattened into a single string rather than a character vector.
Example
names <- c("Ana", "Beto", "Chen")
scores <- c(88, 92, 79)
paste(names, "scored", scores)
# "Ana scored 88" "Beto scored 92" "Chen scored 79"
paste(names, collapse = ", ")
# "Ana, Beto, Chen"
