
The `ISERROR` function in Excel is used to check for any error in a given cell or expression. It returns `TRUE` if there is an error, and `FALSE` otherwise. This function is useful for error handling in your worksheets, allowing you to manage or bypass errors in calculations.
Here’s a basic guide on how to use the `ISERROR` function:
Syntax:
ISERROR(value)
- value: This is the cell or expression you want to test for an error.
Common Use Cases:
- Detect Errors in Formulas:
You can check whether a formula results in an error. For example:
=ISERROR(A1/B1)
This will return `TRUE` if dividing A1 by B1 results in an error (such as division by zero) and `FALSE` otherwise.
- Combine with IF for Error Handling:
Combine `ISERROR` with the `IF` function to return a custom message or alternative result when an error is detected.
=IF(ISERROR(A1/B1), "Error in Calculation", A1/B1)
If there is an error, this will return “Error in Calculation”; otherwise, it will return the result of the division.
- Checking for Errors across a Range:
To check each cell in a range for errors, you might apply `ISERROR` to each cell individually or use it within an `Array Formula` or `Conditional Formatting`.
Example Scenarios:
- Avoid Div/0 Error:
To prevent displaying errors like `#DIV/0!`, wrap your division operation in `ISERROR`.
=IF(ISERROR(A1/B1), "", A1/B1)
This formula returns an empty string if there’s an error and the division result otherwise.
- Analyzing Large Datasets:
Use `ISERROR` to quickly identify problematic cells when analyzing large datasets, especially when you need to ensure data integrity before proceeding with further analysis.
Important Notes:
- `ISERROR` will detect any type of error, including `#N/A`, `#VALUE!`, `#REF!`, `#DIV/0!`, `#NUM!`, `#NAME?`, and `#NULL!`.
- For specific types of error (like `#N/A`), use more tailored functions such as `ISNA`.
- As of Excel 2007, you might also consider using `IFERROR`, which simplifies error handling by combining the check and the alternative outcome in a single function.
By mastering `ISERROR`, you can build more robust and user-friendly Excel models that handle errors gracefully.