---
title: what
framework: Core Services
role: symbol
role_heading: Instance Property
platforms: [Mac Catalyst 17.0+, macOS 10.0+]
path: coreservices/componentparameters/1516601-what
---

# what

Specifies the type of request. Component designers define the meaning of positive values and assign them to requests that are supported by components of a given type. Negative values are reserved for definition by Apple. See “Result Codes” for Apple-defined request code values.

## Declaration

```occ
SInt16 what;
```