Get column index from label in a data frame

Question

Say we have the following data frame:

> df
  A B C
1 1 2 3
2 4 5 6
3 7 8 9

We can select column \'B\' from its index:

&g         


        

Answer 1

I wanted to see all the indices for the colnames because I needed to do a complicated column rearrangement, so I printed the colnames as a dataframe. The rownames are the indices.

as.data.frame(colnames(df))

1 A
2 B
3 C