Looping through list of data frames in R

Question

I have a series of data frames, df1 df2, where each data frame follow this structure:

x <- c(1:5)
y <- c(1:5)
df1 <- data         


        

Answer 1

Just use length(dfList)?

for(i in 1:length(dfList))
{
    a <- grep("One", names(dfList[[i]]))
    ... #etc.
}

Using lapply will be faster.

ChangeNames = function(Data)
{
    a = grep("One", names(Data))
    b = grep("Two", names(Data))
    names(Data)[c(a,b)] <- c("R1", "R2")
    return(Data)
}
lapply(dfList, ChangeNames) #Returns list of renamed data frames.