作业

package wy;
class Person{
private String name;
private int age;
static String city = "A城";
public Person(String name,int age) {
this.name = name;
this.age = age;
}
public String getInfo() {
return "姓名:" + this.name + ",年龄:" + this.age + ",城市:" + city;
}
}
public class StaticDemo02 {
public static void main(String[] args) {
Person per1 = new Person("张三",30);
Person per2 = new Person("李四",31);
Person per3 = new Person("王五",30);
System.out.println("======修改信息之前======");
System.out.println(per1.getInfo());
System.out.println(per2.getInfo());
System.out.println(per3.getInfo());
System.out.println("======修改信息之后======");
Person.city = "B城";
System.out.println(per1.getInfo());
System.out.println(per2.getInfo());
System.out.println(per3.getInfo());

}

}

package wy;
class Single{
private static Single instance = new Single();
private Single() {
}
public static Single getInstance() {
return instance;
}
public void print() {
System.out.println("hello world!!!");
}
}
public class SingleDemo {
public static void main(String[] args) {
Single s = null;
s = Single.getInstance();
s.print();
}

}

package wy;
class Person{
    private String name;
    private static int count;
    public Person() {
        count++;
        this.name = "NONAME - " + count;
    }
    public Person(String name) {
        this.name = name;
    }
    public String getInfo() {
        return "姓名:" + this.name;
    }
}
public class StaticDemo08 {
    public static void main(String[] args) {
        System.out.println(new Person().getInfo());
        System.out.println(new Person("A").getInfo());
        System.out.println(new Person("B").getInfo());
        System.out.println(new Person().getInfo());
    }

}

package wy;
class Person{
private String name;
private static int count;
public Person() {
count++;
System.out.println("产生了" + count + "个实例化对象");
}
public String getInfo() {
return "姓名:" + this.name;
}
}
public class StaticDemo07 {
public static void main(String[] args) {
new Person();
new Person();
new Person();
new Person();
new Person();
}
}

package wy;

public class StaticDemo06 {
public static void main(String[] args) {
for (int x=0;x<args.length;x++) {
System.out.println(args[x] + "、");
}
}
}