findLastIndex  source npm
_.findLastIndex(array, [predicate=_.identity])
This method is like _.findIndex except that it iterates over elements
of collection from right to left.
Arguments
- array (Array) 
The array to search.
 - [predicate=_.identity] (Function|Object|string) 
The function invoked per iteration.
 
Returns (number)
 Returns the index of the found element, else -1.
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];
_.findLastIndex(users, function(o) { return o.user == 'pebbles'; });
// => 2
// using the `_.matches` callback shorthand
_.findLastIndex(users, { 'user': 'barney', 'active': true });
// => 0
// using the `_.matchesProperty` callback shorthand
_.findLastIndex(users, ['active', false]);
// => 2
// using the `_.property` callback shorthand
_.findLastIndex(users, 'active');
// => 0