先看以下代码

public class HelloB extends HelloA{    public HelloB()    {    }    {        System.out.println("I’m B class");    }    static    {        System.out.println("static B");    }    public static void main(String[] args)    {        new HelloB();    }}class HelloA{    public HelloA()    {    }    {        System.out.println("I’m A class");    }    static    {        System.out.println("static A");    }}

执行代码后输出

该问题涉及：静态初始化代码块、构造代码块、构造方法

static {        System.out.println("static A");    }

输出:static A

static {        System.out.println("static B");    }

输出:static B

{        System.out.println("I’m A class");    }

输出:I'm A class

public HelloA() {    }

输出：无

{        System.out.println("I’m B class");    }

输出:I'm B class

public HelloB() {    }

输出：无