// length, string var expected = "3,6,4,3,6,4,3,6,4,3,6,4,"; var actual = ''; function f() { var ss = [ [1, 2, 3], [1, 2, 3, 4, 5, 6], [1, 2, 3, 4] ]; for (var i = 0; i < 12; ++i) { actual += ss[i%3].length + ','; } } f(); assertEq(actual, expected);