---
title: "isError"
description: "Tests to see whether or not the given value's quality is either error."
---

# isError

> Tests to see whether or not the given value's quality is either error.

**This function is used by Ignition's Expression language.**

## Description

Tests to see whether or not the given value's [quality](platform/tags/quality-codes-and-overlays/quality-codes-and-overlays.md) is error.

## Syntax

`isError(value)`

### Parameters

| Type   | Parameter | Description                                |
|--------|-----------|--------------------------------------------|
| Object | `value`   | A value to check if its quality is error.  |

### Returns

**Boolean** - Returns `true` if the value's quality is error, or `false` if it is not.

## Examples

```py title="Code Snippet"
isError({path/to/myTag}) //Returns True if the value's quality is error, False otherwise.
```