我有一个 PriorityQueue of Objects，我需要根据 float values.How 对它进行排序，我应该为它创建一个比较器吗？

Question

我已经为优先级队列创建了一个比较器。

class CompareBySalary implements Comparator<Employee>{
    @Override
    public int compare(Employee e1,Employee e2){
        return e1.salary<e2.salary ? -1 : e1.salary>e2.salary ? 1 : 0;
        
    }
}

class Employee{
    String name;
    float salary;
    Employee(String name,float salary){
        this.name=name;
        this.salary=salary;
    }
}

 public class TryCode{
     
     public static void main(String args[])
     {
        
         Employee e1=new Employee("C",10000);
         Employee e2=new Employee("A",5000.45f);
         Employee e3=new Employee("D",15000);
         Employee e4=new Employee("B",5000.67f);
         Queue<Employee> q=new PriorityQueue(new CompareBySalary());
         q.offer(e1);
         q.offer(e2);
         q.offer(e3);
         q.offer(e4);
         for(Employee e:q)
             System.out.println(e.name);
            
     }
     
     
 }

这给出了 output:A B D C 为什么排序不正确？这是我想念的东西吗？ P.S。我已经尝试过 Float.compare() 它给出了相同的输出。

Answer 1

如下更改域模型：

 class Employee implements Comparable<Employee> {
     private String name;
     private float salary;

     Employee(String name, float salary) {
         this.name = name;
         this.salary = salary;
     }

     public String getName() {
         return name;
     }

     public float getSalary() {
         return salary;
     }

     @Override
     public int compareTo(Employee o) {
         if (o1.getSalary()>o2.getSalary()) {
             return 1;
         } else if (o1.getSalary()<o2.getSalary()) {
             return -1;
         } else {
             return 0;
         }
     }
 }

删除CompareBySalary（你不需要它）

像这样创建您的 PriorityQueue：

PriorityQueue<Employee> q = new PriorityQueue<>(Comparator.comparingDouble(Employee::getSalary));

我有一个 PriorityQueue of Objects，我需要根据 float values.How 对它进行排序，我应该为它创建一个比较器吗？

I have a PriorityQueue of Objects and I need to sort it based on float values.How do I create a comparator for it?

java

priority-queue

comparator

floating-point-comparison