Add leading zero to badly formatted ZIP code

Question

EDIT: I just looked at some more ZIP codes in my file, and learned it is a leading zero these codes are missing.

I have a bunch of zip codes formatted like:

As you can see, these are missing the last 0 to meet the 5-digit ZIP code requirement, because of a formatting issue.

I'm trying to do this:

attach(dat)

for(x in zip){
    if(nchar(x) < 5){
        x <- x*10
    }
}

I've also tried this:

for(x in zip){
    if(nchar(x) < 5){
        zip[x] <- x*10
    }
}

But neither produce the desired result. How can I add the zero to these ZIP codes in R?

if they are numeric `sprintf("%05d", c(1234, 01234, 12345))` works but depending on your platform `sprintf("%05s", c('1234', '01234', '12345'))` will work for strings only sometimes — rawr, Jan 29 '16 at 16:41
For trailing zeros, here's another dupe link http://stackoverflow.com/questions/33656576/use-sprintf-to-add-trailing-zeros — Rich Scriven, Jan 29 '16 at 16:48
@RichardScriven nice dupe find on the trailing zeros -- for some reason I couldn't find that when searching google. — josliber, Jan 29 '16 at 16:49

TJGorrie · Answer 1 · 2016-01-29T16:43:40.767

3

sapply(zip, function(x){if(nchar(x)<5){paste0(x,0)}else{x}})
#zip = a vector

This should work. This will place a trailing "0" on everything <5 characters long. If you want to place a leading 0 use paste0(0,x) instead.

Output will be a vector of strings.

edited Jan 29 '16 at 16:43

answered Jan 29 '16 at 16:37

TJGorrie

386
3
13

score 1 · Accepted Answer · answered Jan 29 '16 at 16:40

Are you sure they are missing the final 0, and not the initial 0? A final zero in a number is meaningful, whereas a leading zero does nothing to change the value of a number, and would be dropped by R.

What I would recommend is converting the data into either character or factor, and then using a function to add a zero to those zip codes less than 10000 (thus having only four digits, rather than the desired five). It would look something like this:

    zip <- c(8974, 8974, 4350, 4350, 7623, 55111, 87969)
    zip <- as.character(zip)
    for(i in 1:length(zip)){
        if(as.numeric(zip[i]) < 10000){
            zip[i] <- paste0("0", zip[i])
        }
    }
    zip

Either way, you shouldn't need to keep the zip codes as numeric values, because you shouldn't be doing mathematical operations on them. They're just geographic labels, so having them as characters or factors shouldn't cause any problems.

Add leading zero to badly formatted ZIP code

2 Answers2