如何用Array和ArrayList做同样的事情？

Question

因此，我有一个面向对象的课程，我的任务是建立一个抽象的雇员类，而不是为其做基础类。 这部分很简单，之后，我必须制作一个“雇员”类型的对象数组，并使用整个多态事物来相应地初始化所有基类。

这是我在主程序中编写的代码：

Scanner input = new Scanner (System.in);

    int Size;
    System.out.println("Enter Array Size");
    Size = input.nextInt();

    Employee [] Array = new Employee [Size];

    int i;
    int A;

    System.out.println("Key: ");
    System.out.println("Press 1 for Salaried Employee.");
    System.out.println("Press 2 for Hourly Employee.");
    System.out.println("Press 3 for Commision Employee.");
    System.out.println("Press 4 for Base Plus Commision Employee.");


    String Name;
    String SSN;
    double wage;
    double hours;
    double salary;
    int Sales;
    double CRate;
    double BaseSalary;

    for (i = 0; i < Array.length; i++ ) {
        A = input.nextInt();
        if (A == 1) {

            do {
                System.out.println("Enter Name");
                input.nextLine();
                Name = input.nextLine();
            } while (Name == "");

            do {
                System.out.println("Enter Social Security Number");
                SSN = input.nextLine();
            } while (SSN == "");

            Array [i] = new Salaried_Employee(Name, SSN);

            System.out.println("Initial Earnings!" +Array[i].Earnings());


        }
        if (A == 2) {
            do {
                System.out.println("Enter Name");
                input.nextLine();
                Name = input.nextLine();
            } while (Name == "");

            do {
                System.out.println("Enter Social Security Number");
                SSN = input.nextLine();
            } while (SSN == "");

            System.out.println("Enter Wage!");
            wage = input.nextDouble();

            System.out.println("Enter hours!");
            hours = input.nextDouble();

            Array [i] = new Hourly_Employee (Name, SSN, wage, hours);
        }

        if (A == 3) {
            do {
                System.out.println("Enter Name");
                input.nextLine();
                Name = input.nextLine();
            } while (Name == "");

            do {
                System.out.println("Enter Social Security Number");
                SSN = input.nextLine();
            } while (SSN == "");

            System.out.println("Enter Sales!");
            Sales = input.nextInt();

            System.out.println("Enter Commision Rate!");
            CRate = input.nextDouble();

            Array [i] = new Comission_Employee (Name, SSN, Sales, CRate);
        }

        if (A == 4) {
            do {
                System.out.println("Enter Name");
                input.nextLine();
                Name = input.nextLine();
            } while (Name == "");

            do {
                System.out.println("Enter Social Security Number");
                SSN = input.nextLine();
            } while (SSN == "");

            System.out.println("Enter Sales!");
            Sales = input.nextInt();

            System.out.println("Enter Commision Rate!");
            CRate = input.nextDouble();

            System.out.println("Define the base salary");
            BaseSalary = input.nextDouble();

            Array [i] = new BassPlus_CommEmployee (Name, SSN, Sales, CRate, BaseSalary);
        }
    }

现在，我必须通过数组列表执行完全相同的操作。 我已经解决了这个问题，但是我不知道如何制作Employee类型的ArrayList。

请帮忙！！

Answer 1

List<Employee> employeeList = new ArrayList<Employee>();

编辑：

employeeList.add(new BassPlus_CommEmployee (Name, SSN, Sales, CRate, BaseSalary));
employeeList.add(new Hourly_Employee (Name, SSN, wage, hours));

等等

我认为Employee是Superclass 。 我认为这是因为您在代码中使用了这个确切的代码段。

Answer 2

ArrayList是一个Object ，它包含其他Object 。 因此，您必须调用方法以用Array代替分配。

array[i] = new Employee(); 例如可以转换为arraylist.add(new Employee())

然后，您需要找到如何get值以转置Employee e = array[i]

不要忘记不要使用空ArrayList 。