# ExpressionFunction class

Namespace: [Grasshopper2.Types.Functions.Standard](https://developer.rhino3d.com/api/gh2/namespace/grasshopper2.types.functions.standard.md) · Assembly: [Grasshopper2](https://developer.rhino3d.com/api/gh2/assembly/grasshopper2.md)

```cs
[IoId("00000000-7cab-4a56-832a-dd827c5db3df")]
public sealed class ExpressionFunction : FunctionWithCaching
```

Represents an immutable expression equation. This equation specifically doesn't allow for custom variable resolvers as the results are cached.

## Constructors

- [ExpressionFunction](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.standard.expressionfunction/ctor.md): (3 overloads)

## Properties

- [Expression](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.standard.expressionfunction/expression.md): Gets the expression inside this function.
- [Notation](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.standard.expressionfunction/notation.md): Gets the notation for this function. Notation is aimed at humans and does not need to return a parseable string.
- [Ui](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.standard.expressionfunction/ui.md)

## Methods

- [Store](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.standard.expressionfunction/store.md)
- [Y](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.standard.expressionfunction/y.md): Evaluate this function at a given x parameter. This method may return NaN values or even throw. The caller is responsible for handling any and all failure cases.

## Inherited Members

- From [FunctionWithCaching](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.functionwithcaching.md): [Derivative](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.functionwithcaching/derivative.md), [Integral](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.functionwithcaching/integral.md), [Nomen](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.functionwithcaching/nomen.md), [EmitDerivative](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.functionwithcaching/emitderivative.md), [EmitIntegral](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.functionwithcaching/emitintegral.md)
- From [Function](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.function.md): [Asymptotes](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.function/asymptotes.md), [AutoCoDomain](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.function/autocodomain.md), [DomainEstimate](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.function/domainestimate.md), [Holes](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.function/holes.md), [Integrate](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.function/integrate.md), [Poles](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.function/poles.md), [YYYY](https://developer.rhino3d.com/api/gh2/type/grasshopper2.types.functions.function/yyyy.md)