# CreateVariable(string,IType,IConvertible,string?)

Method in [Declaration](https://docs.yarnspinner.dev/api/csharp/yarn.compiler/yarn.compiler.declaration)

## Summary

Creates a new instance of the [Declaration](https://docs.yarnspinner.dev/api/csharp/yarn.compiler/yarn.compiler.declaration) class, using the given name, type and default value.

```csharp
public static Declaration CreateVariable(string name, IType type, IConvertible defaultValue, string? description = null)
```

## Parameters

| Name                                                                       | Description                                                                                                          |
| -------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------- |
| `string` name                                                              | The name of the new declaration.                                                                                     |
| [Yarn.IType](https://docs.yarnspinner.dev/api/csharp/yarn/yarn.itype) type | The type of the declaration.                                                                                         |
| `System.IConvertible` defaultValue                                         | The default value of the declaration. This must be a string, a number (integer or floating-point), or boolean value. |
| `string` description                                                       | The description of the new declaration.                                                                              |

## Returns

A new instance of the [Declaration](https://docs.yarnspinner.dev/api/csharp/yarn.compiler/yarn.compiler.declaration) class.