---
title: vDSP_Length
framework: Kernel
role: symbol
role_heading: Type Alias
platforms: [macOS 10.13+]
path: kernel/vdsp_length
---

# vDSP_Length

Used for numbers of elements in arrays and indices of elements in arrays. It is also used for the base-two logarithm of numbers of elements.

## Declaration

```occ
typedef unsigned long vDSP_Length;
```