---
title: "hasChanged"
---

# hasChanged

> **This function is used by Ignition's Expression language.**
> Description
> :::note
> This function is only available in [Transaction Group Expression Items](sql-bridge-transaction-groups/understanding-transaction-groups/expression-items/expression-items.md) and [Expression Tags](tags/creating-memory-expression-and-query-tags/creating-memory-expression-and-query-tags.md).
> :::

**This function is used by Ignition's Expression language.**
## Description
:::note
This function is only available in [Transaction Group Expression Items](sql-bridge-transaction-groups/understanding-transaction-groups/expression-items/expression-items.md) and [Expression Tags](tags/creating-memory-expression-and-query-tags/creating-memory-expression-and-query-tags.md).
:::

This function returns True if the given value has changed since the last time the Expression Item was run. Setting the optional boolean argument "include quality" to true means a quality change will make this function return true.

## Syntax
`hasChanged(value[, includeQuality])`

- Parameters

    - object **value** - The number value to check for change

    - bool **includeQuality** - Optional. A flag that indicates if a quality change will also trigger this tag.

- Results
    - bool - True if the value has changed since the last time the expression was evaluated, False if not.

## Examples
```python title="Code Snippet"
hasChanged({reference to another Expression Item}) //would return true if the referenced value has changed since the last group execution
```