Just change the indexes. i and j....in the loop, plus if you're dealing with Strings you have to use concat and initialize the variable to an empty Strong otherwise you'll get an exception.
String string="";
for (int i = 0; i<array.length; i++){
for (int j = 0; j<array[i].length; j++){
string = string.concat(array[j][i]);
}
}
System.out.println(string)