2.1.23 [ECMA-262/5] Section 15.4.4.15, Array.prototype.lastIndexOf ( searchElement [ , fromIndex ] )

V0024:

The specification states:

 NOTE The lastIndexOf function is intentionally generic; it does not require that its this value be an Array object. Therefore it can be transferred to other kinds of objects for use as a method. Whether the lastIndexOf function can be applied successfully to a host object is implementation-dependent.

IE9 Mode, IE10 Mode, IE11 Mode, and EdgeHTML Mode (All Versions)

The lastIndexOf method can be applied to a host object; however, some host objects may reject such an application.