--- title: "isUncertain" description: "Tests to see whether or not the given value's quality is Uncertain." --- # isUncertain > Tests to see whether or not the given value's quality is Uncertain. **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 Uncertain ## Syntax `isUncertain(value)` ### Parameters | Type | Parameter | Description | |--------|-----------|--------------------------------------------------| | Object | `value` | A value to check if its quality is uncertain. | ### Returns **Boolean** - Returns true if the value's quality is uncertain, or false if it is not. ## Examples ```py title="Code Snippet" isUncertain({path/to/myTag}) //Returns True if the value's quality is uncertain, False otherwise. ```