How to format currency values in valueBox shinydashboard?

Question

I'm trying to write a dashboard with shinydashboard in R to display some values using renderValueBox and valueBoxOutput. These values are not hardcoded but are being scraped from another source daily. These values are currency numbers and should be reporting like $XXX,XXX.XX but instead I see XXXXXX.XX. Is there a way, like a wrapper, to easily format those values? Otherwise I've thought of brute forcing some regex on it with gsub...but ew. Please and thanks :)

Answer 1

Discovered the function prettyNum(): this function is amazing for simple conversion to comma separated numerics.

> prettyNum(56789, big.mark = ",")
> 56,789

Answer 2

Another way is to use the {scales} package and the dollar_format() function. This function is a labelling function factory, in the sense that it creates other functions.

I usually need to output numbers in euros, so I defined the following function:

euro_format <- scales::dollar_format(
  prefix = "\u20ac", # the euro symbol
  suffix = "",
  big.mark = ",",
  decimal.mark = ".",
  accuracy = 1
)

>euro_format(20842)
[1] "€20,842"