如何在 Java 中使用 TreeMap 进行循环

Question

I've been trying to print out a Map to a string but at the same time adding additional item in the process. This is what I'm trying to achieve this: "---\\n---\\n---\\n" But some how it returns like this: "\\n---\\n---\\n---" Anyone have any idea how to fix this?

  //this is my TreeMap
   {
        board.put(0,"-");
        board.put(1,"-");
        board.put(2,"-");
        board.put(3,"-");
        board.put(4,"-");
        board.put(5,"-");
        board.put(6,"-");
        board.put(7,"-");
        board.put(8,"-");
    }

//this is the part I'm trying to work on
StringBuilder result = new StringBuilder();
        for ( position = 0; position <= 8; position++) {
            if(position % 3 == 0){
                result.append("\n");
            }
            result.append(board.get(position));
        }
        return result.toString();

Answer 1

0 is divisible by 3. In the initial state, your for loop executes the if statement because 0 % 3 == 0 is true . Change your if to this:

if(position != 0 && position % 3 == 0)

Or you can start position from 1 and handle the 0th input by yourself before the for loop.