【填空題】讀下面程序,寫出程序運行結(jié)果。 class Father { int num1=0; public Father(){ System.out.println("num1:"+num1);} public Father(int num1){ this.num1=num1; System.out.println("num1:"+num1); } } class Son extends Father{ int num2=10; public Son(){System.out.println("num2:"+num2);} public Son(int i,int j){ super(i); num2=j; System.out.println( "num1:"+num1+",num2:"+num2); } } public class Demo{ public static void main(String []args){ Father father=new Father(); Son son=new Son(); Son son1=new Son(20,30); } } 運行結(jié)果為: