# ReadULong()

> Reads an ulong and advances the current read position by the number of bytes in an ulong.

## Definition

* **Type:** Method
* **Namespace:** [Unity.Entities.Serialization](/engine/7000.0/script-reference/unity/entities/serialization.md)
* **Assembly:** UnityEngine.EntitiesModule

```csharp
public ulong ReadULong()
```

### Returns

| Type                                                          | Description    |
| ------------------------------------------------------------- | -------------- |
| [ulong](https://learn.microsoft.com/dotnet/api/system.uint64) | The read data. |