2021-10-20

public class 十二十 {
    public static void main(String[] args)
    {int a=10;{
        a=20;
        int c=30;
    }
    int b=20;
        System.out.println(c);

    }
}

class Dog{
    private String name;
    private int age;
    {
        System.out.println("dog类调用");
    }
    public Dog(String name,int age){
        System.out.println("start dog 构造");
        this.name=name;
        this.age=age;
    }
}


public class 十二十 {
    public static void main(String[] args)
    {   Dog dog=new Dog("hh",3); }
}

class Dog{
    private String name;
    private int age;
    static {
        System.out.println("静态块");
    }
    {
        System.out.println("dog类 构造块");
    }
    public Dog(String name,int age){
        System.out.println("start dog 构造");
        this.name=name;
        this.age=age;
    }
}


public class 十二十 {
    public static void main(String[] args)
    {   Dog dog=new Dog("hh",3);
    Dog dog1=new Dog("aa",2);
    }
}

`class Dog{
private String name;
private int age;
public static int A=10;

static {
    A=20;
    System.out.println("静态块");
}
{
    System.out.println("dog类 构造块");
}
public Dog(String name,int age){
    System.out.println("start dog 构造");
    this.name=name;
    this.age=age;
}

}

public class 十二十 {
public static void main(String[] args)
{ Dog dog=new Dog(“hh”,3);{ 十二十 t1=new 十二十(“aa”,23);
System.out.println(t1);}
}
}
`

public class ToString
{private String name;
    private int age;

    public ToString(String name,int age){
        this.name=name;
        this.age=age; }
   public String toString(){
       String str="name"+name+"age"+age;
       return str;
        }
   public static void main(String[] args){
        ToString t1=new ToString("kk",79);
       System.out.println(t1);
   }
}

在这里插入图片描述

package test;class Dog{
    private String name;
    private int age;
    public static int A=10;

    static {
        A=20;
        System.out.println("静态块");
    }
    {
        System.out.println("dog类 构造块");
    }
    public Dog(String name,int age){
        System.out.println("start dog 构造");
        this.name=name;
        this.age=age;
    }
}

public class SHIERSHI {
}

package test;

public class Test {

    public static void main(String[] args){
        System.out.println(Dog.A);
    }
}