java - java中严格使用compareTo按2个条件排序

Question

    public int compareTo(T o){

      if (this.getId().charAt(0) < o.getId() ){
         return 1;
      }else{
         return -1;
      }

      //Id data = a, b, f, z
      //num data = 1, 2, 4, 8

      //i want to sort the list according to their id first. then also sort it with their 'num' after sorting with their id first
         //sort id first. sort according to num after
   }

}

我想先根据 ID 对列表进行排序。然后根据num。我会怎样..

Answer 1

尝试以下代码片段。

public int compareTo(Person o){

    int idResult=id.compareTo(o.getId();
    if (idResult == 0) {//same
        return Integer.compare(this.num, o.num);//compare numbers
    }
    return idResult;//else return resut of id comparison
}