_.lastIndexOf(获取元素的索引值)
_.lastIndexOf(array, value, [fromIndex=array.length-1])_.lastIndexOf([1, 2, 1, 2], 2);
// => 3
// Search from the `fromIndex`.
_.lastIndexOf([1, 2, 1, 2], 2, 2);
// => 1Last updated
_.lastIndexOf(array, value, [fromIndex=array.length-1])_.lastIndexOf([1, 2, 1, 2], 2);
// => 3
// Search from the `fromIndex`.
_.lastIndexOf([1, 2, 1, 2], 2, 2);
// => 1Last updated