union()
union(x, y) Returns:
vector · Updated March 13, 2026 · Base Functions sets vectors union base
The union() function returns all unique elements that appear in either of two vectors. It is a convenient way to merge sets of values without keeping duplicates.
Syntax
union(x, y)Parameters
| Parameter | Type | Description |
|---|---|---|
x | vector | First input vector |
y | vector | Second input vector |
Examples
Basic usage
x <- c(1, 2, 3)
y <- c(3, 4, 5)
union(x, y)
# [1] 1 2 3 4 5Character vectors
a <- c("apple", "banana")
b <- c("banana", "cherry")
union(a, b)
# [1] "apple" "banana" "cherry"Handling duplicates
x <- c(1, 1, 2, 2)
y <- c(2, 2, 3, 3)
union(x, y)
# [1] 1 2 3Common Patterns
Combining multiple vectors
a <- c(1, 2)
b <- c(2, 3)
c <- c(3, 4)
union(union(a, b), c)
# [1] 1 2 3 4Unique values from multiple sources
# Two data sources with overlapping IDs
ids1 <- c("user_1", "user_2", "user_3")
ids2 <- c("user_3", "user_4", "user_5")
union(ids1, ids2)
# [1] "user_1" "user_2" "user_3" "user_4" "user_5"