R function with no return value

by

You need to understand the difference between a function returning a value, and printing that value. By default, a function returns the value of the last expression evaluated, which in this case is the assignment

arg <- arg + 3

(Note that in R, an assignment is an expression that returns a value, in this case the value assigned.) This is why data <- derp(500) results in data containing 503.

However, the returned value is not printed to the screen by default, unless you isolate the function’s final expression on its own line. This is one of those quirks in R. So if you want to see the value:

derp <- function(arg)
{
    arg <- arg + 3
    arg
}

or just

derp <- function(arg)
arg + 3

More Related Contents:

  1. Create a function within a function [closed]
  2. how to apply a function on a data set?
  3. How can I view the source code for a function?
  4. How to use R’s ellipsis feature when writing your own function?
  5. data.table objects assigned with := from within function not printed
  6. Update data frame via function doesn’t work
  7. Returning multiple objects in an R function [duplicate]
  8. What ways are there to edit a function in R?
  9. How to create an R function programmatically?
  10. dplyr: “Error in n(): function should not be called directly”
  11. converting multiple columns from character to numeric format in r
  12. Function to calculate R2 (R-squared) in R
  13. Reading multiple files and calculating mean based on user input
  14. Apply a function to every row of a matrix or a data frame
  15. Finding out which functions are called within a given function [duplicate]
  16. How do I override a non-visible function in the package namespace?
  17. What is the meaning of the dollar sign “$” in R function()?
  18. How to compare functions?
  19. Return a data frame from function
  20. R: Obtaining Rules from a Function
  21. Object not found error with ddply inside a function
  22. “Correct” way to specifiy optional arguments in R functions
  23. R: x ‘probs’ outside [0,1]
  24. R function not returning values
  25. Using get() with replacement functions
  26. Getting a function name as a string
  27. Run a custom function on a data frame in R, by group
  28. How to pass aes parameters of ggplot to function
  29. How to use data.table within functions and loops?
  30. Test if an argument of a function is set or not in R

Leave a Comment