R for Everyone: Advanced Analytics and Graphics, 2nd Edition

8. Writing R functions

If we find ourselves running the same code repeatedly, it is probably a good idea to turn it into a function. In programming it is best to reduce redundancy whenever possible. There are several reasons for doing so, including maintainability and ease of reuse. R has a convenient way to make functions, but it is very different from other languages, so some expectation adjustment might be necessary.

8.1 Hello, World!

This would not be a serious book about a programming language if we did not include a “Hello, World!” example, so we will start with that. Let’s build a function that simply prints “Hello, World!” to the console.

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> say.hello  <- function() + { +     print("Hello, World!") + }