# ObjCObject.signature

Read native method type information.

```js
object.signature(selector)
```

## Arguments

| Argument | Type | Meaning |
| --- | --- | --- |
| `selector` | string | Exact selector. |

## Returns

Object {returnType, argumentTypes}: native Objective-C type-encoding strings, with the implicit receiver/selector arguments omitted. Missing or unsupported selectors can throw.

## Example

```js
const text = ObjC.call("NSString", "stringWithString:", "Hello");
try { console.log(text.signature("length")); }
finally { text.release(); }
```

## Notes

Start with [Objective-C step by step](/doc/objc). Here, object means a proxy returned by ObjC/RemoteObjC, not a global named ObjCObject.

[All JavaScript APIs](https://mcp.applesauceos.com/doc/api.md) · [Automation playbook](https://mcp.applesauceos.com/doc/ai.md)