---
title: "index(for:)"
framework: arkit
role: symbol
role_heading: Instance Method
path: "arkit/arskeletondefinition/index(for:)"
---

# index(for:)

Returns the index for a given joint identifier.

## Declaration

```swift
@nonobjc func index(for jointName: ARSkeleton.JointName) -> Int
```

## Discussion

Discussion This function returns NSNotFound if an invalid joint name is passed in.

## See Also

### Getting Joint Information

- [jointNames](arkit/arskeletondefinition/jointnames.md)
- [jointCount](arkit/arskeletondefinition/jointcount.md)
- [parentIndices](arkit/arskeletondefinition/parentindices-u2u9.md)