Microsoft Office

Part IV
Using Advanced Excel Features
FIGURE 25.6
Using data validation to prevent duplicate entries in a range.
Accepting text that begins with A
The following Data Validation formula demonstrates how to check for a specific character. In this case,
the formula ensures that the user’s entry is a text string that begins with the letter A (either uppercase or
lowercase).
=LEFT(A1)=”a”
This formula assumes that the active cell in the selected range is cell A1.
The following formula is a variation of this validation formula. In this case, the formula ensures that the
entry begins with the letter A and contains exactly five characters.
=COUNTIF(A1,”A????”)=1
Accepting only a date that’s a Monday
The following Data Validation formula ensures that the cell entry is a date, and the date is a Monday.
=WEEKDAY(A1)=2
This formula assumes that the active cell in the selected range is cell A1. It uses the WEEKDAY function,
which returns 1 for Sunday, 2 for Monday, and so on.
Accepting only values that don’t exceed a total
Figure 25.7 shows a simple budget worksheet, with the budget item amounts in the range B1:B6. The total
budget is in cell E5, and the user is attempting to enter a value in cell B4 that would cause the total to
exceed the budget. The following Data Validation formula ensures that the sum of the budget items does
not exceed the budget:
=SUM($B$1:$B$6)