---
title: "class_getVersion(_:)"
framework: Objective-C Runtime
role: symbol
role_heading: Function
platforms: [iOS 2.0+, iPadOS 2.0+, Mac Catalyst 13.1+, macOS 10.0+, tvOS 9.0+, visionOS 1.0+, watchOS 1.0+]
path: "objectivec/class_getversion(_:)"
---

# class_getVersion(_:)

Returns the version number of a class definition.

## Declaration

```swift
func class_getVersion(_ cls: AnyClass?) -> Int32
```

## Parameters

- `cls`: A pointer to an doc://com.apple.objectivec/documentation/ObjectiveC/Class data structure. Pass the class definition for which you wish to obtain the version.

## Return Value

Return Value An integer indicating the version number of the class definition.

## Discussion

Discussion You can use the version number of the class definition to provide versioning of the interface that your class represents to other classes. This is especially useful for object serialization (that is, archiving of the object in a flattened form), where it is important to recognize changes to the layout of the instance variables in different class-definition versions. Classes derived from the Foundation framework NSObject class can obtain the class-definition version number using the getVersion class method, which is implemented using the class_getVersion function.

## See Also

### Working with Classes

- [class_getName(_:)](objectivec/class_getname(_:).md)
- [class_getSuperclass(_:)](objectivec/class_getsuperclass(_:).md)
- [class_setSuperclass(_:_:)](objectivec/class_setsuperclass(_:_:).md)
- [class_isMetaClass(_:)](objectivec/class_ismetaclass(_:).md)
- [class_getInstanceSize(_:)](objectivec/class_getinstancesize(_:).md)
- [class_getInstanceVariable(_:_:)](objectivec/class_getinstancevariable(_:_:).md)
- [class_getClassVariable(_:_:)](objectivec/class_getclassvariable(_:_:).md)
- [class_addIvar(_:_:_:_:_:)](objectivec/class_addivar(_:_:_:_:_:).md)
- [class_copyIvarList(_:_:)](objectivec/class_copyivarlist(_:_:).md)
- [class_getIvarLayout(_:)](objectivec/class_getivarlayout(_:).md)
- [class_setIvarLayout(_:_:)](objectivec/class_setivarlayout(_:_:).md)
- [class_getWeakIvarLayout(_:)](objectivec/class_getweakivarlayout(_:).md)
- [class_setWeakIvarLayout(_:_:)](objectivec/class_setweakivarlayout(_:_:).md)
- [class_getProperty(_:_:)](objectivec/class_getproperty(_:_:).md)
- [class_copyPropertyList(_:_:)](objectivec/class_copypropertylist(_:_:).md)