var arr = [            ["a", "b"],            ["1", "2"],            ["d"]        ];        var sarr = [            []        ];        for (var i = 0; i < arr.length; i++) {            var tarr = [];            for (var j = 0; j < sarr.length; j++)                for (var k = 0; k < arr[i].length; k++)                    tarr.push(sarr[j].concat(arr[i][k]));            sarr = tarr;        }        alert(sarr.join("\n"));