If you want to test a cell and take some action if the cell is blank (empty), you can use the IF function.
In the example shown column D contains a date indicating when a task was completed. In column E, a formula checks for blank cells in column D. If a cell is blank, the result is a status of "Open". If the cell contains a value (a date in this case, but it could be any value) the formula assigns status of "Closed". The formula in cell E5 is:
The logical expression ="" can be thought of as meaning "is empty"
The effect of showing "Closed" in light gray is accomplished with a conditional formatting rule.
If you only want to display a value if a cell is blank, you can replace the "value if false" argument in the IF function with an empty string (""). The formula would then be:
Excel contains a function made to test for blank cells called ISBLANK. To use the ISBLANK function in this case, instead of the ="" syntax, you can revise the formula as follows: