primes <- c(2, 5, 7)
cat("primes =", primes, "\n")
# Not changed in place: assign the result
primes <- c(primes, 11)
# primes = 2 5 7 11
cat("primes =", primes, "\n")
# After the first element
primes <- append(primes, 3, after = 1)
# primes = 2 3 5 7 11
cat("primes =", primes, "\n")
# By value
primes <- primes[primes != 2]
# primes = 3 5 7 11
cat("primes =", primes, "\n")
# By index
primes <- primes[-2]
# primes = 3 7 11
cat("primes =", primes, "\n")
primes <- c(primes, 13, 17)
# primes = 3 7 11 13 17
cat("primes =", primes, "\n")
# The last one, and the vector without it
last <- primes[length(primes)]
primes <- head(primes, -1)
# last = 17
# primes = 3 7 11 13
cat("last =", last, "\n")
cat("primes =", primes, "\n")
# Every match goes, not only the first
repeated <- c(7, 3, 7)
repeated <- repeated[repeated != 7]
# repeated = 3
cat("repeated =", repeated, "\n")
# Trap: -which() with no match removes everything
nothing <- primes[-which(primes == 99)]
str(nothing)