int lastIndexOf(E element, [ int start ])

Returns the last index of element in this list.

Searches the list backwards from index start to 0.

The first time an object o is encountered so that o == element, the index of o is returned.

List<String> notes = ['do', 're', 'mi', 're'];
notes.lastIndexOf('re', 2); // 1

If start is not provided, this method searches from the end of the list./Returns

notes.lastIndexOf('re');  // 3

Returns -1 if element is not found.

notes.lastIndexOf('fa');  // -1

Source

int lastIndexOf(E element, [int start]);