类初始化步骤

public class Instace1 {
static{
System.out.println(1);
}
{
System.out.println(2);
}


public Instace1() {
System.out.println(3);
}


{
System.out.println(4);
}


public static void main(String[] args) {
new Instace1();
new Instace1();
}

}

输出结果：

1
2
4
3
2
4
3