ISERROR function

The ISERROR function in Excel is used to check whether a value or expression results in any type of error, including #N/A. It returns TRUE if the value is an error and FALSE otherwise.

Syntax:

ISERROR(value)

Arguments:

• value: The cell reference, value, or expression you want to check for an error.

Error Types Caught by ISERROR:

ISERROR can catch all types of errors, including:

• #DIV/0! (Division by zero)
• #VALUE! (Invalid value)
• #REF! (Invalid cell reference)
• #NAME? (Invalid function or name)
• #NUM! (Invalid numeric value)
• #NULL! (Null intersection)
• #N/A (Value not available)

Examples:

Example 1: Division by zero

• Formula:

  =ISERROR(1/0)
  

• Result: TRUE (since 1/0 results in a #DIV/0! error).

Example 2: Valid number

• Formula:

  =ISERROR(100)
  

• Result: FALSE (since 100 is not an error).

Example 3: #N/A error

• Formula:

  =ISERROR(NA())
  

• Result: TRUE (since #N/A is considered an error in ISERROR).

Use Cases:

1. Error Handling: Use ISERROR to catch and handle errors in formulas:

   =IF(ISERROR(A1/B1), "Error Detected", A1/B1)
   

   This avoids Excel’s default error messages and displays custom text instead of errors.

2. Formulas with Multiple Calculations: Trap errors when performing multiple calculations, such as:

   =IF(ISERROR(A1/B1), "Invalid Division", A1/B1)
   

Key Points:

1. ISERROR vs. ISERR:
   • ISERROR catches all errors, including #N/A.
   • ISERR catches all errors except #N/A.
2. Error Handling with IFERROR:
   • If you want to handle errors more easily in formulas, use IFERROR instead:

   =IFERROR(A1/B1, "Error")
   

   This provides a simpler way to handle any type of error without checking explicitly.