function types.isExternal
Usage in Deno
```typescript import { types } from "node:node__util.d.ts"; ```
isExternal(object: unknown): boolean
Returns `true` if the value is a native `External` value.
A native `External` value is a special type of object that contains a
raw C++ pointer (`void*`) for access from native code, and has no other
properties. Such objects are created either by Node.js internals or native
addons. In JavaScript, they are [frozen](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/freeze) objects with a`null` prototype.
```c
#include
#include
napi_value result;
static napi_value MyNapi(napi_env env, napi_callback_info info) {
int* raw = (int*) malloc(1024);
napi_status status = napi_create_external(env, (void*) raw, NULL, NULL, &result);
if (status != napi_ok) {
napi_throw_error(env, NULL, "napi_create_external failed");
return NULL;
}
return result;
}
...
DECLARE_NAPI_PROPERTY("myNapi", MyNapi)
...
```
```js
const native = require('napi_addon.node');
const data = native.myNapi();
util.types.isExternal(data); // returns true
util.types.isExternal(0); // returns false
util.types.isExternal(new String('foo')); // returns false
```
For further information on `napi_create_external`, refer to `napi_create_external()`.
boolean