# ExpressionReport class

Namespace: [Grasshopper2.Data](https://developer.rhino3d.com/api/gh2/namespace/grasshopper2.data.md) · Assembly: [Grasshopper2](https://developer.rhino3d.com/api/gh2/assembly/grasshopper2.md)

```cs
public sealed class ExpressionReport : IExpressionReport
```

Collates all messages and errors that occur while applying an expression to a tree.

## Properties

- [ErrorCount](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/errorcount.md): Gets the number of error messages in this report.
- [Errors](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/errors.md): Iterate over all error messages.
- [Failures](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/failures.md): Gets the number of times the expression threw exceptions.
- [NullsCreated](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/nullscreated.md): Gets the number of non-null items that were converted into nulls by the expression.
- [NullsRemoved](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/nullsremoved.md): Gets the number of null items that were converted into non-null items by the expression.
- [Successes](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/successes.md): Gets the number of times the expression was successfully applied.
- [WarningCount](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/warningcount.md): Gets the number of warning messages in this report.
- [Warnings](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/warnings.md): Iterate over all warning messages.

## Methods

- [AddError](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/adderror.md): Add an error message.
- [AddFailure](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/addfailure.md): Increment the failure counter.
- [AddNullCreated](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/addnullcreated.md): Increment the null created counter.
- [AddNullRemoved](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/addnullremoved.md): Increment the null removed counter.
- [AddSuccess](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/addsuccess.md): Increment the success counter.
- [AddWarning](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/addwarning.md): Add a warning message.
- [Merge](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.expressionreport/merge.md): Merge data from another report.