JS_AliasElement 编辑

Obsolete since JSAPI 8
This feature is obsolete.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.

Create an aliased index entry for an existing numeric property of a native object.

Syntax

JSBool
JS_AliasElement(JSContext *cx, JSObject *obj,
    const char *name, jsint alias);

Description

JS_AliasElement assigns an alternate index number for an element or numeric property associated with a native object. obj is the object to which the element belongs. name is the element's current index in the object, and alias is the alternate index to assign to the element.

This feature is deprecated, meaning that it is currently supported only for backward compatibility with existing applications. Future versions of the engine may no longer support this function.

An alias does not replace an element's current index number; it supplements it, providing a second way to reference the element. If the alias is successfully created and associated with the property, JS_AliasElement returns JS_TRUE. Adding an alias element does not change the element array length.

If the property name you specify does not exist, JS_AliasElement reports an error, and returns JS_FALSE. If the element is currently out of scope, already exists, or the alias itself cannot be assigned to the element, JS_AliasElement does not report an error, but returns JS_FALSE.

Once you create an alias, you can reassign it to other elements as needed. Aliases can also be deleted. Deleting an alias does not delete the element to which it refers.

See Also

• JS_DefineElement
• JS_DeleteElement
• JS_GetArrayLength
• JS_GetElement
• JS_IsArrayObject
• JS_LookupElement
• JS_NewArrayObject
• JS_SetArrayLength
• JS_SetElement
• bug 576034