How do you remove blank rows or columns from a dataset?

Microsoft Excel - Interview Questions and Answers

Removing blank rows or columns is a common data cleaning task in Excel. Here's a breakdown of effective methods:

Removing Blank Rows :

Using "Go To Special":
- This is a very efficient method for removing scattered blank rows.
- Steps:
  1. Select the range of data.
  2. Press Ctrl + G (or F5) to open the "Go To" dialog box.
  3. Click "Special...".
  4. Select "Blanks" and click "OK". This will select all blank cells within your selected range.
  5. Right-click on any of the selected blank cells, and choose "Delete...".
  6. Select "Entire row" and click "OK".
Using Filters:
- This method is helpful when you want to visually inspect the blank rows before deleting them.
- Steps:
  1. Add filters to your data (Data tab > Filter).
  2. Click the filter dropdown in a column that should not have blank values.
  3. Uncheck "Select All", and then check "(Blanks)". Click "OK". This will display only the blank rows.
  4. Select the visible blank rows, right-click, and choose "Delete Row".
  5. Clear the filter.
Using a Helper Column and COUNTA:
- This is useful for more complex scenarios.
- Steps:
  1. Add a helper column next to your data.
  2. In the first cell of the helper column, enter a formula like =COUNTA(A1:Z1) (adjust the range to cover all columns in your data).
  3. Drag the formula down to apply it to all rows.
  4. Filter the helper column for values of 0 (indicating completely blank rows).
  5. Delete the visible rows.
  6. Remove the helper column.

Removing Blank Columns :

The process for removing blank columns is very similar to removing blank rows.
Using "Go To Special":
- Follow the same steps as for blank rows, but after selecting "Blanks", choose "Entire column" when deleting.
Filtering:
- If you have a row that should contain data in all columns, you can filter that row, and then delete the visible columns that are blank.

Important Notes :

Always make a backup of your data before performing any bulk deletion operations.
Consider the impact of deleting rows or columns on any formulas or charts that reference your data.
When using the "Go to Special" method, be careful to only select the range of data that you want to check for blanks. If you have data outside of that range that also contains blanks, it will also be selected.
VBA macros can also be created to automate these tasks, especially for very large datasets.