Java调用类打印输出结果

/**
*@author Prannt
*调用类打印姓名和年龄
*简单方法和Getter/Setter方法
*/

//简单方法
public class Person {
     
    String name;
    int age;

    public void showName() {
     
        System.out.println("我叫：" + name +"，" +  "年龄是：" + age + "岁。");
    }
}

public class Demo01Person {
     
    public static void main(String[] args) {
     
        Person one = new Person();
        one.name = "尼古拉斯·赵四";
        one.age = 20;
        one.showName();
    }
}

//方法二：Getter/Setter，并用private关键字将需要保护的成员变量进行修饰
public class Trial {
     

    private String name;
    private int age;

    public Trial() {
     
    }

    public Trial(String name, int age) {
     
        this.name = name;
        this.age = age;
    }

    public String getName() {
     
        return name;
    }

    public void setName(String name) {
     
        this.name = name;
    }

    public int getAge() {
     
        return age;
    }

    public void setAge(int age) {
     
        this.age = age;
    }
}


public class Demo04Trial {
     
    public static void main(String[] args) {
     
        Trial tr1 = new Trial();
        tr1.setName("尼古拉斯·赵四");
        tr1.setAge(20);
        System.out.println("姓名是：" + tr1.getName() + "，" + "年龄是：" + tr1.getAge() + "岁。");

    }
}

//方法三，遍历集合
// Getter/Setter部分同方法二
public class Demo02ArrayListStudent {
     
    public static void main(String[] args) {
     
        ArrayList<Student> list = new ArrayList<>();
        
        Student one = new Student("尼古拉斯·赵四",20);
        list.add(one);

        //遍历集合
        //之所以写list.size而不写1，是因为考虑到打印多个人的名字和年龄
        for (int i = 0; i < list.size(); i++) {
     
            Student stu = list.get(i);
            System.out.println("姓名是：" + stu.getName() + "，年龄是：" + stu.getAge() + "岁。");
        }
    }
}