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Create a new Array
object.
Syntax
JSObject * JS_NewArrayObject(JSContext *cx, const JS::HandleValueArray& contents); // Added in SpiderMonkey 31 JSObject * JS_NewArrayObject(JSContext *cx, size_t length); // Added in SpiderMonkey 31 JSObject * JS_NewArrayObject(JSContext *cx, int length, jsval *vector); // Obsolete since JSAPI 30
Name | Type | Description |
---|---|---|
cx |
JSContext * |
The context in which to create the new array. Requires request. In a JS_THREADSAFE build, the caller must be in a request on this JSContext . |
contents |
JS::HandleValueArray& |
Reference to the initial values for the array's elements. Added in SpiderMonkey 31 |
length |
size_t or int |
The length of the new array. This must not be negative. |
vector |
jsval * |
Pointer to the initial values for the array's elements, or NULL. Obsolete since JSAPI 30 |
Description
JS_NewArrayObject
with contents
parameter creates a new array object with the specified contents
elements. JS_NewArrayObject
defines an enumerable array element with the value contents[i]
on the new array.
JS_NewArrayObject
with length
parameter creates a new array object with the specified length
; the result is like the JavaScript expression new Array(length)
. The new array has the specified length
, but it doesn't have any elements.
On success, JS_NewArrayObject
returns the new array object. Otherwise it reports an error as though by calling JS_ReportOutOfMemory
and returns NULL
.
Obsolete since JSAPI 30.
JS_NewArrayObject
with length
parameter creates a new array object with the specified length
. If vector
is non-null, then for each index i
from 0
to length - 1
, JS_NewArrayObject
defines an enumerable array element with the value vector[i]
on the new array. (This means that if length
is nonzero and vector
is null, the result is like the JavaScript expression new Array(length)
. The new array has the specified length
, but it doesn't have any elements.)
It is often better to call JS_NewArrayObject(cx, 0, NULL)
, store the returned object in a GC root, and then populate its elements with JS_SetElement
or JS_DefineElement
. This avoids unrooted jsval
s in vector
from being subject to garbage collection until the new object has been populated.
See Also
- MXR ID Search for
JS_NewArrayObject
- bug 969812 - change parameter to
contents