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# NSKeyValueChange

The kinds of changes that can be observed.

```
enum NSKeyValueChange
```

## Overview

These constants are returned as the value for a [`kindKey`](/documentation/Foundation/NSKeyValueChangeKey/kindKey) key in the change dictionary passed to <doc://com.apple.documentation/documentation/ObjectiveC/NSObject-swift.class/observeValue(forKeyPath:of:change:context:)> indicating the type of change made.

## Topics

### Constants

[`NSKeyValueChange.setting`](/documentation/Foundation/NSKeyValueChange/setting)

Indicates that the value of the observed key path was set to a new value. This change can occur when observing an attribute of an object, as well as properties that specify to-one and to-many relationships.

[`NSKeyValueChange.insertion`](/documentation/Foundation/NSKeyValueChange/insertion)

Indicates that an object has been inserted into the to-many relationship that is being observed.

[`NSKeyValueChange.removal`](/documentation/Foundation/NSKeyValueChange/removal)

Indicates that an object has been removed from the to-many relationship that is being observed.

[`NSKeyValueChange.replacement`](/documentation/Foundation/NSKeyValueChange/replacement)

Indicates that an object has been replaced in the to-many relationship that is being observed.


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