Obsolete since JSAPI 26
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
This article covers features introduced in SpiderMonkey 1.8.5
Finds a specified property and retrieves its value or provided default value.
Syntax
bool
JS_GetPropertyDefault(JSContext *cx, JSObject *obj, const char *name, jsval def,
JS::MutableHandle<JS::Value> vp);
bool
JS_GetPropertyByIdDefault(JSContext *cx, JSObject *obj, jsid id, jsval def,
JS::MutableHandle<JS::Value> vp);
| Name | Type | Description |
|---|---|---|
cx |
JSContext * |
A context. Requires request. In a JS_THREADSAFE build, the caller must be in a request on this JSContext. |
obj |
JS::HandleObject |
Object to search on for the property. |
name or id |
const char * or JS::HandleId |
Name of the property to look up. |
def |
JS::HandleValue |
Default value if the property is not found. |
vp |
JS::MutableHandleValue |
Out parameter. On success, *vp receives the current value of the property, or undefined if no such property is found. |
Description
JS_GetPropertyDefault examines a specified JS object obj and its prototype chain for a property with the specified name.
On success, these functions set *vp to the current value of the property, or def if obj has no such property, and return true. On an error or exception, these functions return false, and the value left in *vp is undefined.