JSBool JS_SetElement()

JSBool JS_SetElement(JSContext *cx, JSObject *obj, jsint idx, jsval *vp)

Method; writes a single element of an array object.

JSContext *cx, JSObject *obj, jsint idx, jsval *vp

The cx argument is the opaque JSContext pointer that passes to the JavaScript function.
The obj argument is a pointer to an array object.
The idx argument is an integer index into the array. The first element is index 0, and the last element is index (length -1).
The vp argument is a pointer to a jsval structure whose contents should be copied to the jsval in the array.

A Boolean value: JS_TRUE indicates success; JS_FALSE indicates failure.