Page 210 - Excel 2013 All-in-One For Dummies

192 Cell Editing 101 Undo and Redo
Excel supports multiple levels of undo that you can use to recover from potentially costly editing mistakes that would require data re-entry or exten- sive repair operations. The most important thing to remember about the Undo command is that it is cumulative, meaning that you may have to select it multiple times to reverse several actions that you’ve taken before you get to the one that sets your spreadsheet right again.
You can select the Undo command either by clicking the Undo button on the Quick Access toolbar or by pressing Alt+Backspace or Ctrl+Z. Excel will then reverse the effect of the last edit you made in the worksheet. For example,
if you edit a cell entry and erase some of its text in error, selecting Undo restores the characters that you just erased to the entry. Likewise, if you delete a group of cells by mistake, selecting Undo restores both their con- tents and formatting to the worksheet.
On the Quick Access toolbar, you can click the drop-down button attached to the Undo command button to display a brief menu of the actions that you’ve recently taken in the spreadsheet. Instead of undoing one action at a time, you undo multiple actions by dragging through them in the drop-down menu. As soon as you release the mouse button, Excel then restores the spreadsheet to the state that it was in before you took all the actions that you chose from this drop-down menu.
When you make an editing change in a spreadsheet, the Undo item on the Undo button’s drop-down menu actually changes to reflect the action that you just took. For example, if you delete a group of cells by pressing the Delete key and then open the Undo button’s drop-down menu, the first item on the Undo menu appears as follows:
Clear
If you then apply new formatting to a cell selection, such as assigning a new center alignment, and then open the Undo drop-down menu, the first item on the Undo menu now appears as follows:
Center Alignment
The Undo feature works by storing a “snapshot” of the worksheet in the memory of your computer at each stage in its editing. Sometimes, if you attempt a large-scale edit in a worksheet, Excel will determine that sufficient free memory doesn’t exist to hold a snapshot of the worksheet in its current state and complete the planned editing change as well. For example, this can happen if you try to cut and paste a really large range in a big worksheet.
In such a case, Excel displays an Alert dialog box that indicates a lack of enough memory and asks whether you want to continue without Undo. If you then select the Yes option, Excel completes the planned edit but without the possibility of you being able to reverse its effects with Undo. Before you