//var a = new Array(5,"5",3,false,4,5,undefined,9)
//a.lastIndexOf(5);
5
//a.lastIndexOf(5, 1);
0
//a.lastIndexOf(5, 2);
0
//a.lastIndexOf(5, 6);
5
//a.lastIndexOf(5, 10);
5
//a.lastIndexOf(true);
-1
//a.lastIndexOf(undefined);
6
//a.lastIndexOf("5");
1
