Return empty cell from formula in Excel

You're going to have to use VBA, then. You'll iterate over the cells in your range, test the condition, and delete the contents if they match.

Something like:

For Each cell in SomeRange
  If (cell.value = SomeTest) Then cell.ClearContents
Next

Yes, it is possible.

It is possible to have a formula returning a trueblank if a condition is met. It passes the test of the ISBLANK formula. The only inconvenience is that when the condition is met, the formula will evaporate, and you will have to retype it. You can design a formula immune to self-destruction by making it return the result to the adjacent cell. Yes, it is also possible.

All you need is to set up a named range, say GetTrueBlank, and you will be able to use the following pattern just like in your question:

=IF(A1 = "Hello world", GetTrueBlank, A1)

Step 1. Put this code in Module of VBA.

Function Delete_UDF(rng)
    ThisWorkbook.Application.Volatile
    rng.Value = ""
End Function

Step 2. In Sheet1 in A1 cell add named range GetTrueBlank with the following formula:

=EVALUATE("Delete_UDF("&CELL("address",Sheet1!A1)&")")

That's it. There are no further steps. Just use self-annihilating formula. Put in the cell, say B2, the following formula:

=IF(A2=0,GetTrueBlank,A2)

The above formula in B2 will evaluate to trueblank, if you type 0 in A2.

You can download a demonstration file here.

In the example above, evaluating the formula to trueblank results in an empty cell. Checking the cell with ISBLANK formula results positively in TRUE. This is hara-kiri. The formula disappears from the cell when a condition is met. The goal is reached, although you probably might want the formula not to disappear.

You may modify the formula to return the result in the adjacent cell so that the formula will not kill itself. See how to get UDF result in the adjacent cell.

I have come across the examples of getting a trueblank as a formula result revealed by The FrankensTeam here: https://sites.google.com/site/e90e50/excel-formula-to-change-the-value-of-another-cell

Excel does not have any way to do this.

The result of a formula in a cell in Excel must be a number, text, logical (boolean) or error. There is no formula cell value type of "empty" or "blank".

One practice that I have seen followed is to use NA() and ISNA(), but that may or may not really solve your issue since there is a big differrence in the way NA() is treated by other functions (SUM(NA()) is #N/A while SUM(A1) is 0 if A1 is empty).