Return all values ​​in the function by entering "ALL"

Question

I have a function that lists all state postal codes and populations of each postal code when a state abbreviation is entered (for example, "KY" or "AL").

I want to return all zip codes and population groups when "ALL" is entered, but I cannot figure out how to do this. I tried writing in a for loop in a function to achieve this without success.

Here is the function:

StatePop1 <- function(StAbb="KY"){
  library(rjson)

  St <- c('AL','AK','AZ','AR','CA','CO','CT','DE','FL','GA','HI','ID','IL','IN','IA','KS','KY','LA','ME','MD','MA','MI','MN','MS','MO','MT','NE','NV','NH','NJ','NM','NY','NC','ND','OH','OK','OR','PA','RI','SC','SD','TN','TX','UT','VT','VA','WA','WV','WI','WY')
  FI <- c('01','02','04','05','06','08','09','10','12','13','15','16','17','18','19','20','21','22','23','24','25','26','27','28','29','30','31','32','33','34','35','36','37','38','39','40','41','42','44','45','46','47','48','49','50','51','53','54','55','56')
  FIPS.table <- data.frame(St,FI,stringsAsFactors = FALSE)
  StAbb <- toupper(StAbb)
  fips_code <- FIPS.table[FIPS.table$St == StAbb,"FI"]
  json_file <- paste("http://api.census.gov/data/2010/sf1?get=P0010001&for=zip+code+tabulation+area:*&in=state:",fips_code,sep="")
  json_data <- fromJSON(file=json_file)
  Pop <- as.data.frame(do.call("rbind", json_data), stringsAsFactors = FALSE)
  names(Pop) <- c("Population","FIPS","ZipCode")
  Pop <- Pop[-1,]
  Pop$Population <- as.numeric(Pop$Population)
  Pop$ZipCode <- as.character(Pop$ZipCode)
  Pop$State <- StAbb
  Pop <- Pop[,c("State","ZipCode","Population")]

  return(Pop)
}

Any help would be appreciated.

Answer 1

, , "", ( state.abb). jsonlite, , .

StatePop1 <- function(StAbb="KY"){
  library(jsonlite)
  if (length(StAbb) == 1 && StAbb == "ALL") StAbb <- state.abb  # check for ALL
  FI <- c('01','02','04','05','06','08','09','10','12','13','15','16','17','18','19','20','21','22','23','24','25','26','27','28','29','30','31','32','33','34','35','36','37','38','39','40','41','42','44','45','46','47','48','49','50','51','53','54','55','56')
  FIPS.table <- data.frame(St=state.abb, FI, stringsAsFactors = FALSE)
  StAbb <- toupper(StAbb)
  fips_code <- FIPS.table[FIPS.table$St %in% StAbb,"FI"]  # change to %in%
  json_file <- paste("http://api.census.gov/data/2010/sf1?get=P0010001&for=zip+code+tabulation+area:*&in=state:",fips_code,sep="")
  json_data <- lapply(json_file, jsonlite::fromJSON)
  Pop <- data.frame(do.call(rbind, json_data), stringsAsFactors = FALSE)  # dont need as.data.frame
  names(Pop) <- c("Population","FIPS","ZipCode")
  Pop <- Pop[-1,]
  Pop$Population <- as.numeric(Pop$Population)
  Pop$ZipCode <- as.character(Pop$ZipCode)
  Pop$State <- FIPS.table[match(Pop$FIPS, FIPS.table$FI), "St"]  # match states
 Pop <- Pop[,c("State","ZipCode","Population")]
  return(Pop)
}

## Example, now passing any of the following should work
res <- StatePop1('KY')
res <- StatePop1(c('NH','KY'))
res <- StatePop1('All')