# ObjCObject.toJSON

Copy a supported Foundation value when JSON.stringify serializes a proxy.

```js
object.toJSON()
```

## Arguments

No arguments.

## Returns

Copied Foundation data: string, boolean, number, array, plain object or null. Large integers become BigInt, or decimal strings if BigInt is unavailable.

## Example

```js
const dictionary = ObjC.create("NSMutableDictionary");
try {
  dictionary.set("message", "Hello");
  console.log(JSON.stringify(dictionary)); // {"message":"Hello"}
} finally { dictionary.release(); }
```

## Notes

JSON.stringify calls this automatically. Unsupported native objects or BigInt values can still fail serialization. object is a returned proxy, not a global named ObjCObject.

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