# PingPong(float, float)

> PingPong returns a value that increments and decrements between zero and the length. It follows the triangle wave formula where the bottom is set to zero and the peak is set to length.

## Definition

* **Type:** Method
* **Namespace:** [UnityEngine](/engine/6000.0/script-reference/unityengine.md)
* **Assembly:** UnityEngine.CoreModule

```csharp
public static float PingPong(float t, float length)
```

### Parameters

**** (\[float]\(https\://learn.microsoft.com/dotnet/api/system.single)): **** (\[float]\(https\://learn.microsoft.com/dotnet/api/system.single)): 

### Returns

| Type                                                          | Description |
| ------------------------------------------------------------- | ----------- |
| [float](https://learn.microsoft.com/dotnet/api/system.single) |             |

### Remarks

PingPong requires the value t to be a self-incrementing value. For example, Time.time and Time.unscaledTime.

The example below shows a simple use case with the light intensity going from 0 to 8 to 0 continuously.

```csharp
using UnityEngine;

public class PingPongExample : MonoBehaviour
{
    Light myLight;

    void Start()
    {
        myLight = GetComponent<Light>();
    }

    void Update()
    {
        myLight.intensity = Mathf.PingPong(Time.time, 8);
    }
}
```

The example below shows some outputs as example.

```csharp
using UnityEngine;

public class OutputExample : MonoBehaviour
{
    void Start()
    {
        // Prints 2
        Debug.Log(Mathf.PingPong(2, 5));

        // Prints 3
        Debug.Log(Mathf.PingPong(7, 5));

        // Prints 1
        Debug.Log(Mathf.PingPong(11, 5));
    }
}
```