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int[] arr = {-1, 5, -2, 10};
System.out.println("排序前:" + Arrays.toString(arr));
Arrays.sort(arr);
System.out.println("排序後:" + Arrays.toString(arr));

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Integer[] arr = {-1, 5, -2, 10};
System.out.println("排序前:" + Arrays.toString(arr));
Arrays.sort(arr, new Comparator<Integer>() {
  @Override
  public int compare(Integer o1, Integer o2) {
    return o2 - o1;
  }
});
System.out.println("排序後:" + Arrays.toString(arr));

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public class Test {
  public static void main(String[] args) {
    int[] arr = {-1, 5, 1, 10, 0, 7};
    // 由小到大
    MyArrays.sort(arr, new Comparator() {
      @Override
      public int compare(Object o1, Object o2) {
        // 自動拆箱
        int i1 = (Integer) o1;
        int i2 = (Integer) o2;
        return i1 - i2;
      }
    });
    System.out.println("排序後 : " + Arrays.toString(arr));
  }
}
class MyArrays {
  public static void sort(int[] arr, Comparator comparator) {
    int loop_count = arr.length - 1;
    for (int i = loop_count; i > 0; i--) {
      for (int j = 0; j < i; j++) {
        // arr[j] - arr[j + 1] 傳回 正數 ，代表arr[j] > arr[j + 1]
        // arr[j] - arr[j + 1] 傳回 負數 ，代表arr[j] < arr[j + 1]
        if(comparator.compare(arr[j] , arr[j + 1]) > 0) {
          // 交換
          int temp = arr[j];
          arr[j] = arr[j + 1];
          arr[j + 1] = temp;
        }
      }
    }
  }
}

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class MyDate2 {
  private int year;
  private int mon;
  private int day;

  public int getYear() {
    return year;
  }

  public int getMon() {
    return mon;
  }

  public int getDay() {
    return day;
  }

  public MyDate2(int year, int mon, int day) {
    this.year = year;
    this.mon = mon;
    this.day = day;
  }

  @Override
  public String toString() {
    return "\nMyDate2{" +
        "year=" + year +
        ", mon=" + mon +
        ", day=" + day +
        '}';
  }
}

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public class Test {
  public static void main(String[] args) {
    // 透過匿名類別建立物件
    Comparator<MyDate2> comparator = new Comparator<MyDate2>() {
      @Override
      public int compare(MyDate2 o1, MyDate2 o2) {
        // 由小到大 o1 - o2
        int diff_y = o1.getYear() - o2.getYear();

        // 不相等代表比較出結果，直接傳回比較結果
        // 之後的程式就沒必要再比較。
        if (diff_y != 0) {
          return diff_y;
        }

        int diff_m = o1.getMon() - o2.getMon();
        if (diff_m != 0) {
          return diff_m;
        }

        int diff_day = o1.getDay() - o2.getDay();
        if (diff_day != 0) {
          return diff_day;
        }
        return 0;
      }
    };

    // 建立Array，裡面的內容是沒按照年月日順序
    MyDate2[] arr = {
        new MyDate2(2000, 11, 10),
        new MyDate2(2000, 1, 1),
        new MyDate2(2000, 3, 1)
    };

    // 陣列排序，把Comparator傳入。
    Arrays.sort(arr, comparator);
    System.out.println(Arrays.toString(arr));
  }
}

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public class Test {
  public static void main(String[] args) {
    MyDate2 myDate2 = new MyDate2(2000, 11, 11);
    MyDate2 another = new MyDate2(2000, 11, 10);
    // 透過匿名類別建立物件
    Comparator<MyDate2> comparator = new Comparator<MyDate2>() {
      @Override
      public int compare(MyDate2 o1, MyDate2 o2) {
        // 由大到小
        int diff_y = o2.getYear() - o1.getYear();
        
        if (diff_y != 0) {
          return diff_y;
        }

        int diff_m = o2.getMon() - o1.getMon();
        if (diff_m != 0) {
          return diff_m;
        }

        int diff_day = o2.getDay() - o1.getDay();
        if (diff_day != 0) {
          return diff_day;
        }
        return 0;
      }
    };
    MyDate2[] arr = {
        new MyDate2(2000, 11, 10),
        new MyDate2(2000, 1, 1),
        new MyDate2(2000, 3, 1)
    };
    Arrays.sort(arr, comparator);
    System.out.println(Arrays.toString(arr));
  }
}