Store all column names and its index pairs as a dataframe/dictionary

I tried to get column names and its index, and save the result as a dataframe or dictionary:

df <- data.frame(a=rnorm(10), b=rnorm(10), c=rnorm(10))

How could I do that? Thanks.

column index
a   1
b   2
c   3

>Solution :

data.frame(column = colnames(df), index = seq_along(df))
#   column index
# 1      a     1
# 2      b     2
# 3      c     3