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# encode(_:)

Encodes an object.

```
func encode(_ object: Any?)
```

## Discussion

`NSCoder`’s implementation simply invokes [`encodeValue(ofObjCType:at:)`](/documentation/Foundation/NSCoder/encodeValue(ofObjCType:at:)) to encode `object`. Subclasses can override this method to encode a reference to `object` instead of `object` itself. For example, `NSArchiver` detects duplicate objects and encodes a reference to the original object rather than encode the same object twice.

This method must be matched by a subsequent [`decodeObject()`](/documentation/Foundation/NSCoder/decodeObject()) message.

---

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