The ISNUMBER function's job is to determine if the data in a certain cell is a number or not. If the data is a number, a value of TRUE is returned by the function.
If it is not a number, or the cell is empty, a FALSE value is returned. It should be noted that, for this function, dates and times are considered numbers.
The syntax for the ISNUMBER function is:
= ISNUMBER ( Value )
Value: Refers to the cell reference that is being checked.
Example Using Excel 2007's ISNUMBER Function:
- Type a word, such as " January ", into cell D1.
- Click on cell E1 - the location where the results will be displayed.
- Click on the Formulas tab.
- Choose More Functions > Information from the ribbon to open the function drop down list.
- Click on ISNUMBER in the list to bring up that function's dialog box.
- Click on cell D1 in the spreadsheet to enter the cell reference into the dialog box.
- Click OK.
- The value FALSE should appear in cell E1 because the data in cell D1 is not a number.
- The complete function = ISNUMBER ( D1 ) appears in the formula bar above the worksheet when you click on cell E1.
- To return a value of TRUE in cell E1, type a number in cell D1 or change the cell reference in the function to a cell that contains a number.