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# init(_:)

Creates an instance that uniquely identifies the given class instance.

```
init(_ x: AnyObject)
```

## Parameters

`x`

An instance of a class.

## Discussion

The following example creates an example class `IntegerRef` and compares
instances of the class using their object identifiers and the identical-to
operator (`===`):

```
class IntegerRef {
    let value: Int
    init(_ value: Int) {
        self.value = value
    }
}

let x = IntegerRef(10)
let y = x

print(ObjectIdentifier(x) == ObjectIdentifier(y))
// Prints "true"
print(x === y)
// Prints "true"

let z = IntegerRef(10)
print(ObjectIdentifier(x) == ObjectIdentifier(z))
// Prints "false"
print(x === z)
// Prints "false"
```

---

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