Retain value from nested for loop - r

Question

So basically I am trying the following loop:
rawData = read.csv(file = "SampleData.csv")
companySplit = split(rawData, rawData$Company)
NameOfCompany <- numeric()
DateOfOrder <- character()
WhichProducts <- numeric()
for (i in 1:length(companySplit)){
company_DateSplit = split(companySplit[[i]], companySplit[[i]]$Date)
for (j in 1:length(company_DateSplit)){
WhichProducts[j] <- (paste0(company_DateSplit[[j]]$ID, collapse=","))
DateOfOrder[j] <- (paste0(company_DateSplit[[j]]$Date[1]))
NameOfCompany[j] <- (paste0(companySplit[[i]]$Company[[1]]))
}
}
df <- data.frame(NameOfCompany,DateOfOrder, WhichProducts)
write.csv(df, file = "basket.csv")
If you check basket.csv there is output for only company D. It is not writing because of nesting of for loops I guess. I am not able to get out of it.
I need exact output as basket.csv but for all companies.
Here are the CSVs:
Input Data: Link
Output of code basket.csv: Link
The output should look like this:
Company,Date, All IDs comma seperated.
e.g.
A,Jan-18,(1,2,4)
A,Feb-18,(1,4)
B,Jan-18,(2,3,4)
I'm able to get it from the above code. But Not able to save it in CSV for all A,B,C,D companies. It saves values for only company D which is the last value in looping. (check output file link)

Answer 1

The initial error is that you import your data without the parameter stringsAsFactors = FALSE which happens all the time. Also, looping in R is usually less efficient and harder to reason about than using a more functional approach. I think what you're trying to do can be done with the aggregate function
rawData <- read.csv(file = "SampleData.csv", stringsAsFactors = FALSE)
df <- aggregate(ID ~ Company + Date, data = rawData, FUN = paste, collapse = ",")
colnames(df) <- c("NameOfCompany", "DateOfOrder", "ID")
df = split(df, df$NameOfCompany)
Or using a tidy approach
df <- rawData %>% group_by(Company, Date) %>%
summarise(WhichProducts=paste(ID,collapse=',')) %>%
rename(DateOfOrder = Date) %>%
rename(NameOfCompany = Company) %>%
group_split()