简单工程方法创建测试类中变量创建

在学习简单工程方法,遇到了一点疑问,创建测试类中的第4行代码是什么变量的创建格式,为什么是 “类型 变量名=方法名.方法名()”,等待指点


double stu1 = studentCalculator.studentCalculator(15);

想请教一下这是哪一块的内容,感谢


public class Student implements MovieTicket {
    public double studentCalculator(double price){
        return  price * 0.8;
    }
    public double vipCalculator(double price){
        throw new UnsupportedOperationException();
    }
    public double childCalculator(double price){
        throw new UnsupportedOperationException();
    }
    public double adultCalculator(double price){
        throw new UnsupportedOperationException();
    }
}

public class TicketFactory {
    public static MovieTicket createTicket(String operator){
        switch(operator){
            case "student":
                return new Student();
            case "vip":
                return new Vip();
            case "child":
                return new Child();
            case "adult":
                return new Adult();
            default:
                throw new IllegalArgumentException("Invalid operator: " +operator);

        }
    }
}


public class Test {
    public static void main(String[] args){
        MovieTicket studentCalculator = TicketFactory.createTicket("student");
        double stu1 = studentCalculator.studentCalculator(15);
        System.out.println("\n学生票价格:"+stu1);
    }
}
MovieTicket studentCalculator = TicketFactory.createTicket("student");
double stu1 = studentCalculator.studentCalculator(15);

这两句,第一句中studentCalculator 是类实例化的对象
第二句中studentCalculator.studentCalculator(15),是使用类实例化对象调用类的的方法

之所以你会理解为方法调用方法,是因为实例化的变量名和方法名写成一样的了
你可以换个变量名称去接收实例化的对象,比如:

MovieTicket calculator = TicketFactory.createTicket("student");
double stu1 = calculator.studentCalculator(15);

这样就很容易理解了