Extra Credit Functions Activity

1. Write a function called add_five that takes a number and returns that number plus 5.

add_five <- function(n) {
  return(n + 5)
}
add_five(4)

## [1] 9

2. Write a function check_number that takes a number and returns “Positive” if the number is greater than 0, “Negative” if less than 0, and “Zero” if equal to 0.

check_number <- function(n) {
  if(n > 0)
    return("Positive")
  if(n<0) 
    return("Negative")
  else
    return("Zero")
}
check_number(-2)

## [1] "Negative"

check_number(0)

## [1] "Zero"

check_number(5)

## [1] "Positive"

3. Write a function sum_of_cubes that uses a for loop to calculate the sum of the cubes of numbers from 1 to n.

sum_of_cubes <- function(n) {
  total <- 0
  for(i in 1:n) {
    total <- i^3 + total
  }
  return(total)
}
sum_of_cubes(10)

## [1] 3025

4. Write a function countdown that uses a while loop to print numbers starting from n down to 1, and then returns “Blast off!”.

blast_off <- function(n) {
  print(n)
  while(n != 1) {
    n <- n - 1
    print(n)
  }
  return("Blast Off!")
}
blast_off(10)

## [1] 10
## [1] 9
## [1] 8
## [1] 7
## [1] 6
## [1] 5
## [1] 4
## [1] 3
## [1] 2
## [1] 1

## [1] "Blast Off!"