instance method Array#lastIndexOf
Array#lastIndexOf(item[, offset]) → Number
?) – A value that may or may not be in the array.
Number) – The number of items at the end to skip before beginning the search.
Returns the position of the last occurrence of
item within the
array — or
item doesn't exist in the array.
Array#lastIndexOf acts as an ECMAScript 5 polyfill.
It is only defined if not already present in the user's browser, and it
is meant to behave like the native version as much as possible. Consult
the ES5 specification for more