现有如下包结构: com -- x -- Alpha.class -- y -- Beta.class -- Gamma.class 和类: class Test { Alpha a; Beta b; Gamma c; } 哪三个必须加入到类 Test 中,以使其通过编译?()
class super { public float getNum() {return 3.0f;} } public class Sub extends Super { } Which method, placed at line 6, will cause a compiler error?()
class BaseClass{ private float x= 1.0f; protected void setVar (float f) {x = f;} } class SubClass exyends BaseClass { private float x = 2.0f; //insert code here 8. } Which two are valid examples of method overriding?()
现有: class Banana2 f static int X=2; public static void main (String [] args) { int X=2; Banana2 b=new Banana2(); b.go(x); } static {x+=x; } void go (int x) { ++x; System. out.println (x); } 结果为:()
现有: public class Pet() public class Cat extends Pet{) 执行代码 Cat c- new Cat(); Pet p= (Pet)c; 后下列哪项是正确的?()
现有: class ClassA {} class ClassB extends ClassA {) class ClassC extends ClassA {) 以及: ClassA p0=new ClassA(); ClassB pl=new ClassB(); ClassC p2=new ClassC(); ClassA p3=new ClassB(); ClassA p4=new ClassC(); 下列哪些是正确的?()
现有: 1. class Synapse { 2. protected int gap() { return 7; } 3. } 4. 5. class Creb extends Synapse { 6. // insert code here 7. } 分别插入到第 6 行,哪三行可以编译?()
现有: class Test2 f public static void main (String [] args) { short a,b,C; a=l; b=2; C=a+b; a+=2: } 以上代码中,哪一句是错误的?()
class BaseClass{ private float x= 1.0f; protected void setVar (float f) {x = f;} } class SubClass extends BaseClass { private float x = 2.0f; //insert code here 16. } Which two are valid examples of method overriding?()
现有包结构: com -- x -- Alpha.class -- y -- Beta.class -- Gamma.class 和类: //insert code here import com.*; import com.x.y.*; class Test { Alpha a; Beta b; Gamma c; } 哪两行分别插入后可允许代码编译?()
现有: class TestFoo { int x; String y; int getX() { return x; } String getY() { return y; } void setX(int x) { int z = 7; this.x = x; } } 可以添加多少个修饰符来封装此类?()
现有: interface I { void go(); } abstract class A implements I { } class C extends A { void go(){ } } 结果是什么?()
class BaseClass{ private float x= 1.0f; protected void setVar (float f) {x = f;} } class SubClass extends BaseClass { private float x = 2.0f; //insert code here } Which two are valid examples of method overriding?()
现有: public class Pet() public class Cat extends Pet{) 执行代码 Cat c- new Cat(); Pet p= (Pet)c; 后下列哪项是正确的?()
现有 public class Parentt public void change (int x){) ) public class Child extends Parent{ //覆盖父类change方法 } 下列哪个声明是正确的覆盖了父类的change方法?()
现有: Public/project]class TestFoo { int x; String y; int getX() { return x; } (4,5,6是方法) String getY() { return y; } void setX(int x) { int z = 7; this.x = x; } } Private代表属性封装可以添加多少个修饰符来封装此类?()
现有: class Passer f static final int X=5; public static void main (String [] args) { new Passer().go (x); System. out .print (x); } void go (int x) { System. out .print(x++); } 结果是什么?()
现有如F包结构: com 一一X 一一Alpha.class 一一y I 一一Beta.class l-- Gamma.class 和类: class Test { Alpha a; Beta b; Gamma c; } 哪三个必须加入到类Test中,以使其通过编译?()
现有: 1.class Passer f 2.static final int X=5; 3.public static void main (String [] args) { 4.new Passer().go (x); 5.System. out .print (x); 6. ) 7.void go (int x) { 8.System. out .print(x++); 9.} 10.}结果是什么?()
已知:class A{public:int a;int b();int f();int f(int);int g();};class B{public:char f();int g();private:int a;int b();};class C:public A,public B{};设有:C *pc;则:
看下列程序 package a; class Parent { private int i = 20; protected int j = 30; public int k = 40; int h = 50; } class Child extends Parent { } class GrandSon extends Child { void f() { } } 在子类GrandSon的方法f()中不可以操作的变量是
有如下类定义: class Test { public: Test(){a=0;c=0;} //① int f(in
请写出代码的运行结果。 class A{ int f(int x,int y){ return x+y; } } class B extends A{ int
给定以下代码,以下哪句是正确的?class TestBed {TestBed(){}void f(){ System.out.println(“f()”); }public static void main(String[] args) {TestBed t = new TestBed();t.f();}}class TestDoor