---
title: "class_getInstanceSize(_:)"
framework: Objective-C Runtime
role: symbol
role_heading: Function
platforms: [iOS 2.0+, iPadOS 2.0+, Mac Catalyst 13.1+, macOS 10.5+, tvOS 9.0+, visionOS 1.0+, watchOS 1.0+]
path: "objectivec/class_getinstancesize(_:)"
---

# class_getInstanceSize(_:)

Returns the size of instances of a class.

## Declaration

```swift
func class_getInstanceSize(_ cls: AnyClass?) -> Int
```

## Parameters

- `cls`: A class object.

## Return Value

Return Value The size in bytes of instances of the class cls, or 0 if cls is Nil.

## 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_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)
- [class_addMethod(_:_:_:_:)](objectivec/class_addmethod(_:_:_:_:).md)