How to add commas and 3 trailing zeros to a column in a dataframe?

Question

I have a dataframe in R that contains a column called AverageSalary with just numbers that vary in length from 1-4 integers. I want to add 3 0's to the end of the number regardless of length and add a comma for every 3 integers.

I have tried a concatenation and sprintf (gives me leading zeros). Does anybody have any ideas?

Average Salary Desired Format
             3          3,000
           144        144,000
          5678      5,678,000

Answer 1

Using formatC.

x <- c(3, 144, 5678)

formatC(x*1e3, format='f', digits=0, big.mark=',')
# [1] "3,000"     "144,000"   "5,678,000"

Answer 2

You could also use scales::comma():

library(scales)

comma(AverageSalary * 1000)
# "3,000"     "144,000"   "5,678,000"