现自: 1. interface Color { } 2. interface Weight { } 3. //insert code here 和以下足六个声明: class Boat extends Color, extends Weight { } class Boat extends Color and Weight { } class Boat extends Color, Weight { } class Boat implements Color, implements Weight { } class Boat implements Color and Weight { } class Boat implements Color, Weight { } 分别插入到第3行,有多少行可以编译? ()
第1题:
定义一个类名为MyClass的类,并且该类可被所有类访问,那么该类的正确声明应为()
A、private class MyClass extends Object
B、class MyClass extends Object
C、public class MyClass
D、protected class MyClass extends Object
第2题:
Which three demonstrate an “is a” relationship?()
第3题:
A.public class MinMax<?> {
B.public class MinMax<? extends Number> {
C.public class MinMax<N extends Object> {
D.public class MinMax<N extends Number> {
E.public class MinMax<? extends Object> {
F.public class MinMax<N extends Integer> {
第4题:
现有: 1. abstract class Color2 { 2. //insert code here 3. } 4. 5. public class Blue2 extends Color2 { 6.public String getRGB() { return "blue"; } 7. } 和4个声明: public abstract String getRGB(); abstract String getRGB(); private abstract String getRGB(); protected abstract String getRGB(); 分别插入到第2行,有多少行可以编译?()
第5题:
现在有两个类A、B,以下描述中表示B继承自A的是()
第6题:
1. public interface A { 2. public void doSomething(String thing); 3. } 1. public class AImpl implements A { 2. public void doSomething(String msg) { } 3. } 1. public class B { 2. public A doit() { 3. // more code here 4. } 5. 6. public String execute() { 7. // more code here 8. } 9. } 1. public class C extends B { 2. public AImpl doit() { 3. // more code here 4. } 5. 6. public Object execute() { 7. // more code here 8. } 9. } Which statement is true about the classes and interfaces in the exhibit?()
第7题:
interface Data { public void load(); } abstract class Info { public abstract void load(); } Which class correctly uses the Data interface and Info class?()
第8题:
下列哪个类声明是正确的? ( )
A.abstract class G2 extends superClass1,superClass2{...}
B.abstract public class classmates{...}
C.public final class NewClass extends superClass implemnets Interface1{...}
D.public abstract class String{...}
第9题:
定义一个类名为"MyClass.java"的类,并且该类可被一个工程中的所有类访问,那么该类的正确声明应为()。
第10题:
package sun.scjp; public enum Color { RED, GREEN, BLUE } package sun.beta; // insert code here public class Beta { Color g = GREEN; public static void main( String[] argv) { System.out.println( GREEN); } } The class Beta and the enum Color are in different packages. Which two code fragments, inserted individually at line 2 of the Beta declaration, will allow this code to compile?()