SOURCE

function largestOfFour(arr) {
  
var biao = [];
  
  for (i = 0 ;i < arr.length;i++){
    var count = 0;
    var sum = 0;
    document.write('-----<br>');
		for(j = 0;j < arr[i].length;j++){
      sum += arr[i][j];
      count++;
      //document.writeln(arr[i][j]);
      if(count == 4){
        biao.push(sum);
        h = 0;
        h++;
				document.writeln(h+':'+biao);
        
      }
    }
  }
return biao;
}


largestOfFour([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]]);