# ISERR function

ISERR(value) ISERR(value)

## value

The value to check.

## Returns

Logical

Whether the given value is an error but is not an `#N/A` error ("not available").

Returns whether the given value is an error but is not an `#N/A` error ("not available"). ISERR(NA())ISERR(NA()) returns FALSE. (The NA function returns an `#N/A` error.) However, ISERR(Field1 / Field2)ISERR(Field1 / Field2) returns TRUE when the value of Field2 is 0 or blank, resulting in a `#DIV/0!` error ("division by zero").

Lookup functions like XLOOKUP return `#N/A` errors when a value cannot be found. The ISNA function may be used to detect the `#N/A` error specifically.

This formula returns TRUE, because the sought value, 10, is not part of the { 20, 30 }{ 20; 30 } lookup array given to XLOOKUP:

ISNA(XLOOKUP(10, { 20, 30 }, { 200, 300 }))ISNA(XLOOKUP(10; { 20; 30 }; { 200; 300 }))

ISERR is the opposite of ISNA, meaning that it detects all errors except for `#N/A` errors. Consider this formula:

ISERR(XLOOKUP(Field1 / Field2, { 20, 30 }, { 200, 300 }))ISERR(XLOOKUP(Field1 / Field2; { 20; 30 }; { 200; 300 }))

The preceding formula returns TRUE if the value of Field2 is 0 or blank, resulting in a `#DIV/0!` error, but it returns FALSE if the value resulting from the Field1 / Field2Field1 / Field2 calculation cannot be found in the lookup array.

The ERROR.TYPE function can be used to determine the precise error type.

## Errors are never displayed to your users

When you preview your app, any errors are shown in red. This is meant to help you, the author of the app, determine the cause of potentially unexpected behavior. Errors are also shown when you sign into Calcapp Connect with your credentials and run your own apps.

However, these errors are not shown in shared apps, meaning that errors are never shown to your users. Instead, a field with an error looks like a blank field in shared apps.

If you want to hide errors from showing up in the preview and in Calcapp Connect, use a formula like the following:

## Examples

ISERR(NA())ISERR(NA())

Returns FALSE. (The NA function returns an `#N/A` error.)

ISERR(Field1 / Field2)ISERR(Field1 / Field2)

Returns TRUE when the value of Field2 is 0 or a blank value, resulting in a `#DIV/0!` error ("division by zero").

ISERR({ 4, NA() })ISERR({ 4; NA() })

Returns FALSE, as the array as a whole is not an error.

MAP({ 4 / Field1, NA() }, ISERR(Element))MAP({ 4 / Field1; NA() }; ISERR(Element))

Returns { TRUE, FALSE }{ TRUE; FALSE }, indicating that the first array element is a `#DIV/0!` error and the second array element is a `#N/A` error. (The value of Field1 must be 0 or blank in order for the first array element to be a `#DIV/0!` error.)