Question

I was about to ask another question on SO that this question popped up in my mind. How we define an object with a weird name. For instance, suppose we would like to call an object “test^#”. If I wanted to define it, I would use ” “:

"test^#" <- 10

Now the question is how to call this object?
If we again use ” “, then R considers it as a character string and not the name of an object.
While I see practical applications in being able to use symbols in the object names, but at this point it’s more a question out of my curiosity.

Thanks,

Answer 1

Use backticks:

"test^#" <- 10
ls()
[1] "test^#"

Now use it:

`test^#`
[1] 10

---

You can also use backticks to refer to columns in data frames (or lists) with non-standard names. For example:

iris$`Sepal length` <- iris$Sepal.Length
str(iris)
'data.frame':   150 obs. of  6 variables:
 $ Sepal.Length: num  5.1 4.9 4.7 4.6 5 5.4 4.6 5 4.4 4.9 ...
 $ Sepal.Width : num  3.5 3 3.2 3.1 3.6 3.9 3.4 3.4 2.9 3.1 ...
 $ Petal.Length: num  1.4 1.4 1.3 1.5 1.4 1.7 1.4 1.5 1.4 1.5 ...
 $ Petal.Width : num  0.2 0.2 0.2 0.2 0.2 0.4 0.3 0.2 0.2 0.1 ...
 $ Species     : Factor w/ 3 levels "setosa","versicolor",..: 1 1 1 1 1 1 1 1 1 1 ...
 $ Sepal length: num  5.1 4.9 4.7 4.6 5 5.4 4.6 5 4.4 4.9 ...


summary(iris$`Sepal length`)
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  4.300   5.100   5.800   5.843   6.400   7.900 

---

If you want to something really odd, like embedding backticks in the name, then you may have to use get() to refer to it:

"test^`#" <- 20

get("test^`#")
[1] 20