Being a heavy Eclipse user, I’ve grown
accustomed to its keyboard shortcuts for moving and copying lines of
text. Xcode
doesn’t have a regular editing command for this, but it does offer
similar functionality via user scripts. The Move Line Up and Move
Line Down scripts are already there, just waiting for you to bind keys
to them. Go to the script menu, which is to the left of the Help menu,
and select the Edit User Scripts… menu item. Expand the disclosure
triangle next to Text, and you can set keyboard shortcuts by
double-clicking in the column to the right of the script names. Below is
a screenshot of what the dialog will look like if you follow all of the
instructions in this post.