Little useless-useful R functions – Inserting variable values into strings

Another useless function that could be found in many programming languages. For example typical Python sample, that everyone have encountered would be:

MyName = "Tomaz"
Value_in_string = "My Name is  {} and I write this post.".format(MyName)
print(Value_in_string)

Resulting in a string with:

My Name is Tomaz and I write this post.

So, let’s do something similar in R. We will call this function is cat_v and in most useless way, it looks like:

cat_v <- function(tex){
    rr <- " "
    pos_1 <- which(strsplit(tex, "")[[1]]=="{")
    pos_2 <- which(strsplit(tex, "")[[1]]=="}")
    end_pos <- nchar(tex)
    varname <- substr(tex, pos_1+1, pos_2-1)
    t <- get(eval(varname))
    t1 <- substr(tex, 1, pos_1-1)
    t2 <- substr(tex, pos_2+1, end_pos)
    t1 <- paste0(t1, t, t2)
    cat(t1)
}

Same as with Python, we can do now this with R in same fashion.

# Creating a variable
vv <- "tomaz"

# Running cat function with variable
cat_v("This is text by: {vv} and today is a great day!")
cat_v("This is text by: {vv}")

And result is pretty obvious:

As always, code is available in at the Github in same Useless_R_function repository.

Happy R-coding!