Primality test in R

Trial division, written vectorized so it tests a whole vector at once.

is_prime <- function(n) {
  if (n < 2) {
    return(FALSE)
  }
  if (n < 4) {
    return(TRUE)
  }
  divisors <- 2:floor(sqrt(n))
  all(n %% divisors != 0)
}

Keywords and builtins used here

all
floor
function
if
return
sqrt

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Step 3 of 5 in Flow & functions, step 7 of 20 in Language basics.

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Primality test in other languages

C
Go
Python