{"json_modified": "2016-03-28T07:47:54.313636", "uuid": "61caf96d-db62-4d71-94ef-fab70b443918", "title": "JS_InstanceOf", "url": "/en-US/docs/Mozilla/Projects/SpiderMonkey/JSAPI_reference/JS_InstanceOf", "tags": ["R\u00e9f\u00e9rence", "Reference", "SpiderMonkey", "JSAPI Reference"], "translations": [], "modified": "2015-01-18T12:42:00", "label": "JS_InstanceOf", "localization_tags": [], "locale": "en-US", "id": 1402, "last_edit": "2015-01-18T12:41:52", "summary": "<strong><code>JS_InstanceOf</code></strong> can be used to check whether an object obj is of a particular <code>JSClass</code>. To use it this way, pass <code>NULL</code> for <code>argv</code>. <code>JS_InstanceOf</code> returns <code>true</code> if <code>obj</code> is of the given class and <code>false</code> otherwise. That is, it returns <a href=\"/en-US/docs/Mozilla/Projects/SpiderMonkey/JSAPI_reference/JS_GetClass\" title=\"JS_GetClass returns a pointer to the JSClass associated with a specified JS object, obj. The application must treat the JSClass as read-only. If obj has no JSClass, this returns NULL.\"><code>JS_GetClass(obj) == clasp</code></a>.", "sections": [{"id": "Quick_Links", "title": null}, {"id": "Syntax", "title": "Syntax"}, {"id": "Description", "title": "Description"}, {"id": "See_Also", "title": "See Also"}], "slug": "Mozilla/Projects/SpiderMonkey/JSAPI_reference/JS_InstanceOf", "review_tags": ["technical"]}