Functions Exercise Answers

1. Write a function that will take print out your name and call it myName

myName <- function(){
   
  print("Brian Pattiz")
  
  
}

myName()

## [1] "Brian Pattiz"

2. Write a function that will return the sum of two squares and call it SumofTwoSquares. Test it!

SumofTwoSquares <- function(x, y){
  
  
  return(x^(2) + y^(2))
  
  
}

SumofTwoSquares(3, 3)

## [1] 18

3. Write a function called ReturnNRowNCol that will take a dataframe and return both its number of rows and number of columns in a vector. Test it with the following dataframe:

admits <- data.frame(ADMIT_ID = c(paste0("000", 1:9),"0010"), ACT = round(runif(10, 17, 34)), 
                     HIGH_SCHOOL_DESC = c("Blue Springs South", "Warrensburg High School", "Odessa R-VII SR High School", "Blue Springs South", "Lees Summit North High School", "Lees Summit West High School",
                                      rep("Warrensburg High School", 3), "Platt County R-III High School"), stringsAsFactors = FALSE)

ReturnNRowNCol <- function(df){
  
  numrow <- nrow(df)
  numcol <- ncol(df)
  
  return(c(numrow, numcol))
  
}

ReturnNRowNCol(admits)

## [1] 10  3

4. Write a function that take any list and print if the last element is a character string. Call it isString. Test with x <- list(T, “This is a test”, 4L, 5L, F, T, “This is a string”)

isString <- function(test_list){
  
  len <- length(test_list)

  is.character(test_list[[len]])
  
  
}

x <- list(TRUE, "This is a test", 4L, 5L, F, T, "This is a string")

isString(x)

## [1] TRUE