[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fGsC_SwJWzTXTqBttHmteP1mbeLb1EuDM2f5Rbp631MA":3},{"answer":4,"createTime":5,"id":6,"options":7,"origin":8,"question":15,"related":16,"source":26,"type":109},[],"2024-03-31 18:47:34",136426857,[],{"count":9,"courseId":10,"courseImg":11,"courseName":12,"workId":13,"workName":14},15,"8f39179e8e9bd7589885271226eaaa28","https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F26feeabf4f7b0cfd6c0f37373ddb1520.jpg","面向对象程序设计(Java)","exam_102570348","单元3测试-类对象","下面代码的输出结果是 public class TestStaticMethod{ static int times=100; public static void main(String[] args){ Count myCount1 = new Count(10); Count myCount2 = new Count(); int times = 0; for(int i=0;i<100;i++) increment(myCount1 , times); System.out.println("count is" + myCount1.count); System.out.println("time is"+ TestStaticMethod.times); for(int i=0;i<100;i++) increment(myCount2 , times); System.out.println("count is" + myCount2.count); System.out.println("time is"+ times);} public static void increment(Count c , int times){ c.count++; times++;}} class Count{ int times=10; public int count; Count(int c){ count =c;} Count(){ times++; count =1; System.out.println("time is"+ times);}}",[17,28,37,46,55,64,73,82,91,100],{"answer":18,"createTime":5,"id":19,"options":20,"question":25,"source":26,"type":27},[],136426843,[21,22,23,24],"表达式合法","编译时合法而在运行时可能非法","编译时非法","将构造一个Student对象","类Teacher和Student都是类Person的子类 Person p; Teacher t; Student s; 若p,t和s都是非空值 if(t instanceof Person) { s = (Student)t; } 若默认new时声明的都是本类,这个语句导致的结果是( )","v1",0,{"answer":29,"createTime":5,"id":30,"options":31,"question":36,"source":26,"type":27},[],136426845,[32,33,34,35],"抽象类不能包含抽象方法","接口和抽象类是一回事","抽象类不能实例化,即不能直接调用构造方法生成对象","抽象类可以实例化对象","下列关于抽象类的描述正确的是( )",{"answer":38,"createTime":5,"id":39,"options":40,"question":45,"source":26,"type":27},[],136426846,[41,42,43,44],"一般在创建新对象时,系统会自动调用构造函数","构造函数是类的一种特殊函数,它的方法名必须与类名相同","构造函数的返回类型只能是void型","构造函数的主要作用是完成对类的对象的初始化工作","对于构造函数,下列叙述不正确的是( )",{"answer":47,"createTime":5,"id":48,"options":49,"question":54,"source":26,"type":27},[],136426847,[50,51,52,53],"原来c所指的对象","原来b和c所指的对象","原来a所指的对象","原来b所指的对象","设有Circle类,执行下面语句后,可以被垃圾回收器回收的对象是( ). Circle a=new Circle(); Circle b=new Circle(); Circle c=new Circle(); a = b; a = c; c = null",{"answer":56,"createTime":5,"id":57,"options":58,"question":63,"source":26,"type":27},[],136426848,[59,60,61,62],"static void methoda(){}","final void methoda(){}","static final void methoda(){}","void final methoda(){}","下面方法声明正确但又能被子类重写的是()",{"answer":65,"createTime":5,"id":66,"options":67,"question":72,"source":26,"type":27},[],136426849,[68,69,70,71],"x、y和s都是成员变量","x、y和s都是实例变量","x是实例变量、y是类变量、s是参数","x和y是实例变量、s是参数","参照以下Java代码,以下四个叙述中最确切的是( ) class A{ int x; static int y; void fac(String s){System. out. println("字符串:"+s);} }",{"answer":74,"createTime":5,"id":75,"options":76,"question":81,"source":26,"type":27},[],136426850,[77,78,79,80],"sh和tr分别引用同一类型的不同的对象","sh和tr分别引用不同类型的不同的对象","sh和tr分别引用同一个对象","sh和tr分别引用同一个对象的不同副本","已知Rectangle和Triangle是Shape类的子类,Square是Rectangle的子类.针对下列代码,下面描述正确的是() Triangle tr = new Triangle(); Square sq = new Square(); Shape sh = tr",{"answer":83,"createTime":5,"id":84,"options":85,"question":90,"source":26,"type":27},[],136426851,[86,87,88,89],"Nothing","b is an instance of A followed by b is an instance of C","b is an instance of A","b is an instance of C","根据下列程序代码,选择项描述正确的是() Show the output of running the class Test in the following code lines: interface A { void print(); } class C {} class B extends C implements A { public void print() { } } class Test { public static void main(String[] args) { B b = new B(); if (b instanceof A) System.out.println("b is an instance of A"); if (b instanceof C) System.out.println("b is an instance of C"); } }",{"answer":92,"createTime":5,"id":93,"options":94,"question":99,"source":26,"type":27},[],136426852,[95,96,97,98],"beta gamma","gamma gamma","alpha beta","alpha alpha","下面程序运行结果为(). class Alpha{ String getType(){return "alpha";} } class Beta extends Alpha{ String getType(){return "beta";} } class Gamma extends Beta{ String getType(){return "gamma";} public static void main(String[] args){ Alpha g1=new Beta(); Alpha g2=new Gama(); System.out.println(g1.getType() + "" + g2.getType());} }",{"answer":101,"createTime":5,"id":102,"options":103,"question":108,"source":26,"type":27},[],136426853,[104,105,106,107],"public void getNum(double d){}","public void getNum(){}","public float getNum(){return 4.0f;}","public double getNum(float d){return 4.0d;}","有下面类的定义: Class Super{ Public float getNum(){return 3.0f} } Public class Sub extends Super{ } 下面方法放在画线处会发生编译错误的是( )",2]