Site icon R-bloggers

head and tail for strings

[This article was first published on factbased, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)
Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.

The functions head and tail are very useful for working with lists, tables, data frames and even functions.
But they do not work on strings. It is easy to define such functions

> strtail <- function(s,n=1) {
+   if(n strhead <- function(s,n) {
+   if(n

and start using them:

> strhead("abc", 1)
[1] "a" 
> strhead("abc", -1)
[1] "ab" 
> strtail("abc", 1)
[1] "c" 
> strtail("abc", -1)
[1] "bc" 

It is not a good idea to name these functions head.character and tail.character because this
has unexpected effects if applied to a vector of strings.

Other useful string functions are defined in the the
stringr package.

To leave a comment for the author, please follow the link and comment on their blog: factbased.

R-bloggers.com offers daily e-mail updates about R news and tutorials about learning R and many other topics. Click here if you're looking to post or find an R/data-science job.
Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.