The ISERROR function is an important function in Microsoft Excel that can be used to check whether a cell contains an error value. In this article, we will explain how to use the ISERROR function in Excel and provide some examples to help you understand how it works.

The ISERROR function is a logical function that returns TRUE if a cell contains any error value, including #N/A, #VALUE!, #REF!, #DIV/0!, #NUM!, or #NAME?. If the cell does not contain an error value, it returns FALSE.

The basic syntax of the ISERROR function is as follows:

=ISERROR(value)

The value argument is the cell or range of cells that you want to check for error values. This can be a formula or a value.

Here are some examples of how to use the ISERROR function in Excel:

Example 1:

Suppose you have a formula in cell A1 that divides the value in cell B1 by the value in cell C1, as shown below:

=A1/B1

If the value in cell C1 is zero, the formula will return a #DIV/0! error. To check whether cell A1 contains an error value, you can use the following formula in another cell:

=ISERROR(A1)

This formula will return TRUE if cell A1 contains any error value, including #DIV/0!.

Example 2:

Suppose you have a list of values in cells A1:A5 and you want to check whether any of the cells contain an error value. You can use the following formula:

=IF(COUNTIF(A1:A5,"<>")+COUNTIF(A1:A5,"="&"")=ROWS(A1:A5),"No errors","Errors found")

This formula uses the COUNTIF function to count the number of cells that do not equal "" (blank) or the string ">", and then compares the count to the number of rows in the range. If the count matches the number of rows, it means there are no error values in the range.

Example 3:

Suppose you have a table of data in cells A1:D10 and you want to highlight any cells that contain an error value. You can use conditional formatting to achieve this. Here's how:

- Select the range of cells that you want to apply the conditional formatting to (in this case, A1:D10).
- Go to the Home tab and click on the Conditional Formatting button.
- Select New Rule from the dropdown menu.
- In the New Formatting Rule dialog box, select "Use a formula to determine which cells to format".
- In the "Format values where this formula is true" field, enter the following formula:

=ISERROR(A1)

- Click on the Format button to choose the formatting you want to apply to cells that contain an error value.
- Click on OK to close the dialog boxes.

Now, any cell in the selected range that contains an error value will be highlighted with the formatting you chose.

In conclusion, the ISERROR function is a useful tool in Excel for checking whether a cell contains an error value. It can be used in a variety of ways, including in formulas, conditional formatting, and data validation. By understanding how to use the ISERROR function, you can save time and ensure the accuracy of your calculations in Excel.