Use the DATEDIF function to determine all friends younger than 30 You have the birth dates of your friends listed in a worksheet and want to shade those who are currently younger than 30 years old. Use the TODAY function to determine the actual date and the DATEDIF function to calculate the exact age, then combine those functions with conditional formatting. 4 To determine all friends younger than 30: 1. In a worksheet, enter data in cells A2:B10, as shown in Figure 10-25. 2. Select cells A2:B10. 3. On the Format menu, click Conditional Formatting. 4. Select Formula Is and type the following formula: =DATEDIF($B2,TODAY(),"Y")<30. 5. Click Format. 6. From the Patterns tab, select a color and click OK. 7. Click OK. 270 Chapter 10 Figure 10-25 Use the MONTH and TODAY functions to find birthdays in the current month Use the same list from the previous tip to determine whose birth - day falls in the current month. Use the TODAY function to determine the actual date and the MONTH function to compare the month of everyone’s birthday with the current month, then com - bine those functions with conditional formatting. 4 To determine all friends whose birthday is in the current month: 1. In cell D1 enter the formula TODAY(). 2. Select cells A2:B10. 3. On the Format menu, click Conditional Formatting. 4. Select Formula Is and type the following formula: =(MONTH(TODAY())=MONTH($B2)). 5. Click Format. 6. From the Patterns tab, select a color and click OK. 7. Click OK. Conditional Formatting with Formulas 271 10 Figure 10-26 Use conditional formatting to border summed rows Enhance worksheets with this tip for placing a border on special cells. The worksheet contains daily sales for different teams. Their sales are summed up after a certain period to get a current status. To enhance the visibility of each sum, we want to border it automat - ically through conditional formatting. Use a simple instruction as the condition for conditional formatting and border the row of each cell that meets the desired condition. 4 To border all rows containing a sum: 1. In a worksheet, enter data in cells A1:C11, as shown in Fig- ure 10-27, and select the range A2:C11. 2. On the Format menu, click Conditional Formatting. 3. Select Formula Is and type the following formula: =$B2="sum". 4. Click Format. 5. On the Border tab, click the bottom line in the Border field. 6. Select the color red from the Color drop-down box. 7. Click OK. 272 Chapter 10 Figure 10-27 Use the LEFT function in a product search In this example, you need to find all the product numbers that con - tain the same first three characters. Enter in cell A2 the product number as the search criteria and let Excel find each product that corresponds to the same first three characters. The first three characters of the numbers can be extracted by the LEFT function. The name of the first product appears automatically in cell B2 with the following formula: =VLOOKUP($A$2,$A$5:$B$15,2,FALSE). Use a combination of the LEFT function and conditional formatting to shade each cell that meets the desired condition. 4 To shade product numbers that meet the criteria: 1. In a worksheet, copy the data in cells A4:B15, as shown in Figure 10-28, and select cells A5:B15. 2. On the Format menu, click Conditional Formatting. 3. Select Formula Is and type the following formula: =LEFT($A5,3)=LEFT($A$2,3). 4. Click Format. 5. In the Patterns tab, select a color and click OK. 6. Click OK. Conditional Formatting with Formulas 273 10 Figure 10-28 Use the AND function to detect empty rows in a range The last tip in this chapter marks all empty cells in a range. Use a combination of the AND function and conditional formatting to shade each cell that meets the desired condition. 4 To detect empty rows in a range: 1. In a worksheet, copy the data in cells A1:B12, as shown in Figure 10-29, and select the range A2:B12. 2. On the Format menu, click Conditional Formatting. 3. Select Formula Is and type the following formula: =AND($A3>($A2+1),$B3>($B2+1)). 4. Click Format. 5. From the Patterns tab, select a color and click OK. 6. Click OK. 274 Chapter 10 Figure 10-29 Chapter 11 Working with Array Formulas 275 Use the ADDRESS, MAX, and ROW functions to determine the last used cell With this tip, we learn the definition of an array formula. Here, we want to determine the last used cell in a range and shade it. Com - bine the ADDRESS, MAX, and ROW functions as described below to get the desired result. 4 To determine the last used cell in a range and shade it: 1. In column A list any kind of numbers. 2. Select cell B2 and type the following array formula: =ADDRESS(MAX((A2:A100<>"")*ROW(A2:A100)),1). 3. Press <Ctrl+Shift+Enter>. 4. Select cells A2:A11. 5. From the Format menu, select Conditional Formatting. 6. Select Formula Is and type the following formula: =ADDRESS(ROW(),1)=$B$2. 7. Click Format. 8. In the Patterns tab, select a color and click OK. 9. Click OK. Note: As shown in Figure 11-1, Excel automatically inserts the combined functions, which are defined as an array formula between the braces ({ and }). Use an array formula to perform several calculations to generate a single result or multiple results. 276 Chapter 11 Working with Array Formulas 277 11 Figure 11-1 Use the INDEX, MAX, ISNUMBER, and ROW functions to find the last number in a column Use the table from the previous tip and continue with array formu - las. Now we want to determine the last value in column A. Use a combination of the INDEX, MAX, ISNUMBER, and ROW functions inside an array formula to have the desired result displayed in cell B2. Don’t forget to enter the array formula by pressing <Ctrl+Shift+Enter> to enclose it in braces. 4 To determine the last number in a column: 1. In column A list values or use the table from the previous tip. 2. Select cell B2 and type the following array formula: =INDEX(A:A,MAX(ISNUMBER(A1:A1000)*ROW (A1:A1000))). 3. Press <Ctrl+Shift+Enter>. 278 Chapter 11 Figure 11-2 Use the INDEX, MAX, ISNUMBER, and COLUMN functions to find the last number in a row In this example, the last value in each row has to be determined and copied to another cell. To do this, combine the INDEX, MAX, ISNUMBER, and COLUMN functions in an array formula. 4 To determine the last number in a row: 1. Generate a table like that shown in Figure 11-3 using the range A1:F6. 2. In cells A9:A13 enter numbers from 2 to 6. 3. Select cell B9 and type the following array formula: =INDEX(2:2,MAX(ISNUMBER(2:2)*COLUMN(2:2))). 4. Press <Ctrl+Shift+Enter>. 5. Select cells B9:B13. 6. Select Fill and then Down from the Edit menu to retrieve the last value in each of the remaining rows. Working with Array Formulas 279 11 Figure 11-3 [...]... Formatting 7 Select Formula Is and type the following formula: =$F$2=B2 8 Click Format 9 In the Patterns tab, select a color and click OK 11 10 Click OK Working with Array Formulas 281 Figure 11-5 282 Chapter 11 Use the AVERAGE and IF functions to calculate the average of a range, taking zero values into consideration Normally Excel calculates the average of a range without considering empty cells... B2:B7 Right-click in the Excel status bar and select the built-in Average function instead of the usually displayed Sum Working with Array Formulas 283 Use the SUM and IF functions to sum values with several criteria To sum values in a list, the SUMIF function is normally used Unfortunately, it is not that easy to sum values with different criteria Using a combination of different functions in an array... Conditional Formatting 6 Select Formula Is and type the following formula: =AND( $A2>=2500,$A2=2500,IF(A2:A11 . the Excel status bar and select the built-in Average function instead of the usually displayed Sum. Working with Array Formulas 283 11 Figure 11-6 Use the SUM and IF functions to sum values with. Select Formula Is and type the following formula: =$F$2=B2. 8. Click Format. 9. In the Patterns tab, select a color and click OK. 10. Click OK. Working with Array Formulas 281 11 282 Chapter 11 Figure. Formula Is and type the following formula: =$B$12=COLUMN(A1). 7. Click Format. 8. In the Patterns tab, select a color and click OK. 9. Click OK. 280 Chapter 11 Figure 11-4 Use the MIN and IF functions