The Code | Move Statement Up/Down actions are useful for reorganizing code lines, for example for bringing a variable declaration closer to the variable usage.
Select a code fragment and press &shortcut:MoveStatementUp; or &shortcut:MoveStatementDown;.
The following picture shows the initial location of a code fragment:

The results of moving the selected fragment up:

And the results of moving the selected fragment down:

When nothing is selected in the editor, the line at the caret position will be moved.