Writing Functions

Example 1

# Example 1: No arguments
helloworld <- function() {
  print("Hello World!")  
}
helloworld()

Example 2

# Example 2: One argument
helloname <- function(name) {
  print(glue("Hello {name}!"))  
}
helloname("Kai")

Example 3

# Example 3: Return a value
addtax <- function(price) {
  return(round(price * 1.13, 2))
}
addtax(49.99)
addtax(49.99) + addtax(79.99)

Notes

print() vs return(): print() displays a value. return() sends a value back so you can save it or use it in a calculation, as in Example 3.

print() also returns a value. It just doesn’t display it twice. For example, x <- helloname("Kai") prints “Hello Kai” and also saves it in x.

return() is optional. R functions return the result of their last line automatically. Using return() makes it clear what the function gives back.

Technique: Converting data formats, Cleaning data
Tools: R
Data Format: Statistics