Does someone have an idea why this code doesn't sort the employees properly? I need them to be sorted in ascending order by the amount of their salary.

I think I've messed up smth cause I'm storing salaries in doubles. But I really don't know what to do. Plz help.

public static void main(String[] args) {

    List<Employee> employees = new ArrayList<>(List.of(
            new Employee("Steve", 3.1),
            new Employee("Mark", 4.2),
            new Employee("Oliver", 4)));

    System.out.println("Before sorting: "   employees);
    employees.sort(Employee::compareTo);
    System.out.println("After sorting: "   employees);
}

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

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

    @Override
    public int compareTo(Employee employee) {
        return (int) this.salary - (int) employee.salary;
    }

    @Override
    public String toString() {
        return name   " "   Math.round(salary * 100.0) / 100.0; //2 digits after the dot
    }
}

Outpute:

This doesn't work as well

CodePudding user response：

The problem is with your compareTo function. Both 4.2 and 4.0 are just 4s as integers, so your program doesn't swap them.

You need to compare doubles. I think, this one will help you.