已定义类Aclass:class Aclass {private int x = 1;protected int y = 2;public int z = 3;public int sumA(){ return(x +y +z ); }}再通过继承与扩展定义子类Bclass:class Bclass extends Aclass {private
A. s += b;
B. s += x;
C. s += z;
D. s += y;
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下面代码的运行结果为()public class Test {static int age;public static void main (String args []) {age = age + 1;System.out.println(“age=” + age);}}
A. 编译运行后输出 age=0
B. 编译运行后无任何输出
C. 编译出错
D. 编译运行后输出 age=1
有如下类定义,当程序执行到 // doStuff 时,CardBoard类的几个对象中,有()个设置为null? class CardBoard {Short story = 5;CardBoard go(CardBoard cb) {cb = null;return cb;}public static void main(String[] args
A. 0
B. 1
C. 2
D. 编译不通过
下面代码的运行结果为()。public class NumTest{long a[ ] = new long[10];public static void main(String arg[ ] ){System.out.println(a[6]);}}
A. 输出 0
B. 输出 null
C. 出现编译不通过
D. 运行出错
以下程序的执行结果是()class Guy {public Guy(){System.out.print(“111,”);}}class Cowboy extends Guy {public Cowboy(){System.out.print(“222,”);}}class Wrangler extends Cowbo
A. 111,111,222,111,222,333
B. 111,222,333
C. 111,111,222,222,333
D. 编译不通过