How to add leading zeros?

Question

I have a set of data which looks something like this:

anim <- c(25499,25500,25501,25502,25503,25504)
sex  <- c(1,2,2,1,2,1)
wt   <- c(0.8,1.2,1.0,2.         


        

Answer 1

data$anim <- sapply(0, paste0,data$anim)