[R] Moving 2nd column into 1st column using R

[smart hendsome]

Hi R-user,
I have a problem regarding R.  How can I move my 2nd column into 1st column.  For example I have data as below:
 mydf <- data.frame(matrix(1:6, ncol = 2))
 mydf
  X1 X2   1   4   2   5   3   6
I want move my 2nd column become like this:
  X1    1      2    3    4   5   6
Hope anyone can help me. Many thanks.

Zuhri
 
	[[alternative HTML version deleted]]