R Logical Operators

AND, OR, and NOT

! flips a logical value, & requires both sides to be TRUE, and | requires at least one side to be TRUE. These building blocks let you combine multiple conditions into a single test.

!TRUE
TRUE & FALSE
TRUE | FALSE

Element-wise vs Single-Value Operators

& and | compare every element of two vectors and return a vector of results, which is exactly what you want when filtering rows of data. && and || instead look only at the first element of each side and return one single TRUE or FALSE, which is what if() and while() expect their condition to be.

x <- c(TRUE, FALSE, TRUE)
y <- c(TRUE, TRUE, FALSE)
x & y
x[1] && y[1]

Short-Circuit Evaluation

&& and || are short-circuiting: && stops as soon as it hits a FALSE, and || stops as soon as it hits a TRUE, without even looking at the right-hand side. This is more than an optimization — it lets you safely guard a risky check behind a simpler one.

v <- c()
if (length(v) > 0 && v[1] == 5) {
  print("match")
} else {
  print("no match or empty vector")
}