# argumentPosition(forFunction:argument:) Returns the index into the arguments array for the given function argument. ``` func argumentPosition(forFunction function: String? = nil, argument: String) -> Int ``` ## Parameters `function` The function. Specify as `nil` if the graph only contains one function. `argument` The name of the input or output argument. ## See Also [`func BNNSGraphGetArgumentPosition(bnns_graph_t, UnsafePointer?, UnsafePointer) -> Int`](/documentation/Accelerate/BNNSGraphGetArgumentPosition(_:_:_:)) Returns the index into the arguments array for the given function argument. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)