Section 28 Vector: Implicit Coercion

The one exception to this is the special value NA (Not Available) used to signify a missing value
28.1 Example: Implicit coercion
y <- c(TRUE, 2) # numeric
y <- c(1.7, "a") # character
y <- c("a", TRUE) # character
a <- rep(c(T,F), length=5)
b <- c(1:5)
c <- letters[1:5]
a
b
c
c(a,b)
c(a,c)
c(b,c)
c(a,b,c)
a + b
a + c # Error
b + c # Error