objCType

objCType is a method of the NSValue class in Objective-C that returns the Objective-C type encoding for the value stored in the NSValue instance. The return value is a C string (const char *) describing the type, using the same encoding syntax used by the Objective-C runtime.

The type encoding returned by objCType follows the standard Objective-C runtime type encodings. Simple primitive types have single-letter codes, such as i for int, d for double, c for char, and f for float. Object types use @, and pointers are indicated with a leading ^. Structs and unions are encoded with braces and their field encodings, for example, "{CGPoint=dd}" for a CGPoint. The encoding can also represent more complex types, including arrays, unions, and nested structs, using the established encoding rules or the @encode directive.

Usage typically involves inspecting the encoding to determine how to interpret the raw bytes stored in the NSValue, or when constructing an NSValue from raw memory with valueWithBytes:objCType:. Developers often compare the result of objCType with known encodings (such as @encode(type)) to handle values generically or to bridge between Objective-C and C APIs. The method is commonly used in conjunction with other NSValue facilities, such as getValue: to extract the stored data or valueWithBytes:objCType: to create values from raw memory.

Related concepts include the runtime type encodings used by the Objective-C runtime and the @encode directive, which provides the type encoding string for a given C or Objective-C type. objCType is part of the NSValue interface for working with arbitrary binary data in a typed way.