Name of i in loop - R - r

Question

I'm trying to extract the name of the i column used in a loop:
for (i in df){
print(name(i))
}
Python code solution example:
for i in df:
print(i)
PS: R gives me the column values If I use the same code than Python (but python gives just the name).
EDIT: It has to be in a loop. As I will do more elaborate things with this.

Answer 1

for (i in names(df)){
print(i)
}

Answer 2

Just do
names(df)
to print all the column names in df. There's no need for a loop, unless you want to do something more elaborate with each column.
If you want the i'th column name:
names(df)[i]

Answer 3

Instead of looping, you can use the imap function from the purrr package. When writing the code, .x is the object and .y is the name.
df <- data.frame(a = 1:10, b = 21:30, c = 31:40)
library(purrr)
imap(df, ~paste0("The name is ", .y, " and the sum is ", sum(.x)))
# $a
# [1] "The name is a and the sum is 55"
#
# $b
# [1] "The name is b and the sum is 255"
#
# $c
# [1] "The name is c and the sum is 355"
This is just a more convenient way of writing the following Base R code, which gives the same output:
Map(function(x, y) paste0("The name is ", y, " and the sum is ", sum(x))
, df, names(df))

Answer 4

You can try the following code:
# Simulating your data
a <- c(1,2,3)
b <- c(4,5,6)
df <- data.frame(a, b)
# Answer 1
for (i in 1:ncol(df)){
print(names(df)[i]) # acessing the name of column
print(df[,i]) # acessing column content
print('----')
}
Or this alternative:
# Answer 2
columns <- names(df)
for(i in columns) {
print(i) # acessing the name of column
print(df[, i]) # acessing column content
print('----')
}
Hope it helps!