Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

doc: add an example for util.types.isExternal #31173

Closed
Closed
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
30 changes: 30 additions & 0 deletions doc/api/util.md
Original file line number Diff line number Diff line change
Expand Up @@ -1399,6 +1399,35 @@ properties. Such objects are created either by Node.js internals or native
addons. In JavaScript, they are [frozen][`Object.freeze()`] objects with a
`null` prototype.

```c
#include <js_native_api.h>
#include <stdlib.h>
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
BridgeAR marked this conversation as resolved.
Show resolved Hide resolved
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
BridgeAR marked this conversation as resolved.
Show resolved Hide resolved
[`napi_create_external()`][].

### `util.types.isFloat32Array(value)`
<!-- YAML
added: v10.0.0
Expand Down Expand Up @@ -2358,5 +2387,6 @@ util.log('Timestamped message.');
[default sort]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort
[global symbol registry]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/for
[list of deprecated APIS]: deprecations.html#deprecations_list_of_deprecated_apis
[`napi_create_external()`]: n-api.html#n_api_napi_create_external
[semantically incompatible]: https://github.com/nodejs/node/issues/4179
[util.inspect.custom]: #util_util_inspect_custom