The ISBLANK function's job is to check to see if a certain cell is does or does not contain data. If the cell is empty, a value of TRUE is returned by the function.
If it is not empty, the function returns the value of FALSE.
If data is later added to an empty cell the function will automatically update and return a FALSE value.
The syntax for the ISBLANK function is:
= ISBLANK ( Value )
Value: (required) - refers to the value or cell that is being tested.
This argument can be blank, or it can contain data such as text, numbers, error values, logical values, or non-printing characters.
Example Using Excel's ISBLANK Function:
As shown in the image above, this example checks to see whether certain worksheet cells do or do not contain data.
Entering the Data
- Enter the following data into the following cells:
D1 - 3 D2 - leave this cell blank D3 - text
Entering the ISBLANK Function
- Click on cell E1 to make it the active cell - this is where the results of the function will be displayed
- Click on the Formulas tab of the ribbon
- Choose More Functions > Information to open the function drop down list
- Click on ISBLANK in the list to bring up that function's dialog box
- Click on cell D1 in the worksheet to enter the cell reference into the dialog box
- Click OK to complete the function and close the dialog box
- The value FALSE should appear in cell E1 because cell D1 is not empty
- When you click on cell E1 the complete function = ISBLANK ( D1 ) appears in the formula bar above the worksheet
Copying the function using the fill handle
To save time, we can use the fill handle to copy the ISBLANK function in cell E1 to cells E2 and E3.
- Click on cell E1 to make it the active cell
- Place the mouse pointer over the black square in the bottom right corner of cell E1. The pointer will change to a plus sign " + "
- Click the left mouse button and drag the fill handle down to cell E3
- Release the mouse button. Cell E2 should contain the result TRUE since cell D2 is blank and E3 should return FALSE since cell D3 contains the word text
Invisible Characters and ISBLANK
In the image above, the ISBLANK function in cell E4 returns a FALSE value even though cell D4 appears to be blank.
This is not an error because cell D4 contains an invisible character called a non-breaking space ( ).
Non-breaking spaces are one of a number of control characters commonly used in web pages and these characters sometimes end up in a worksheet along with data copied from the web page.
Removing Non-breaking Spaces and other Invisible Characters
If there is no visible data in the cell, removing invisible characters can usually be accomplished simply by clicking on the cell in question and pressing the Delete key on the keyboard.
On the other hand, if you ever have a situation where a cell contains good data as well as non-breaking spaces, it is possible to strip non-breaking spaces from the data you wish to keep.