JAVA认证SCJP认证真题及答案（17）

　　QUESTION NO 141

　　Exhibit:

　　1. class A {

　　2. public String toString () {

　　3. return “4”;

　　4. }

　　5. }

　　6. class B extends A {

　　7. 8. public String toString () {

　　8. return super.toString() + “3”;

　　9. }

　　10. }

　　11. public class Test {

　　12. public static void main(Stringargs) {

　　13. System.out.printIn(new B());

　　14. }

　　15. }

　　What is the result?

　　A. Compilation succeeds and 4 is printed.

　　B. Compilation succeeds and 43 is printed.

　　C. An error on line 9 causes compilation to fail.

　　D. An error on line 14 causes compilation to fail.

　　E. Compilation succeeds but an exception is thrown at line 9.

　　Answer: B

　　QUESTION NO 142

　　Which two statements are true? (Choose Two)

　　A. An anonymous inner class can be declared inside of a method

　　B. An anonymous inner class constructor can take arguments in some situation.

　　C. An anonymous inner class that is a direct subclass that is a direct subclass of Object can implement

　　multiple interfaces.

　　D. Even if a class Super does not implement any interfaces, it is still possible to define an anonymous

　　inner class that is an immediate subclass of Super that implements a single interface.

　　E. Event if a class Super does not implement any interfaces, it is still possible to define an anonymous

　　inner class that is an immediate subclass of Super that implements multiple interfaces.

　　Answer: A, B

　　QUESTION NO 143 www.ExamW.CoM

　　Given:

　　1. public class MethodOver {

　　2. private int x, y;

　　3. private float z;

　　4. public void setVar(int a, int b, float c){

　　5. x = a;

　　6. y = b;

　　7. z = c;

　　8. }

　　9. }

　　Which two overload the setVar method? (Choose Two)

　　A. void setVar (int a, int b, float c){

　　x = a;

　　y = b;

　　z = c;

　　}

　　B. public void setVar(int a, float c, int b) {

　　setVar(a, b, c);

　　}

　　C. public void setVar(int a, float c, int b) {

　　this(a, b, c);

　　}

　　D. public void setVar(int a, float b){

　　x = a;

　　z = b;

　　}

　　E. public void setVar(int ax, int by, float cz) {

　　x = ax;

　　y = by;

　　z = cz;

　　}

　　Answer: B, D

　　QUESTION NO 144

　　Which statements about static inner classes are true? (Choose Two)

　　A. A static inner class requires a static initializer.

　　B. A static inner class requires an instance of the enclosing class.

　　C. A static inner class has no reference to an instance of the enclosing class.

　　D. A static inner class has access to the non-static members of the outer class.

　　E. Static members of a static inner class can be referenced using the class name of the static inner

　　class.

　　Answer: C, E

　　QUESTION NO 145

　　Given:

　　1. public class X {

　　2. public object m () {

　　3. object o = new float (3.14F);

　　4. object oa = new object [1];

　　5. oa[0]= o;

　　6. o = null;

　　7. oa[0] = null;

　　9. return o;

　　9. }

　　10. }

　　When is the float object created in line 3, eligible for garbage collection?

　　A. Just after line 5.

　　B. Just after line 6.

　　C. Just after line 7.

　　D. Just after line 8(that is, as the method returns).

　　Answer: C

　　QUESTION NO 146

　　Which two interfaces provide the capability to store objects using a key-value pair? (Choose Two)

　　A. Java.util.Map.

　　B. Java.util.Set.

　　C. Java.util.List.

　　D. Java.util.StoredSet.

　　E. Java.util.StoredMap.

　　F. Java.util.Collection.

　　Answer: A, E

　　QUESTION NO 147

　　Which interface does java.util.Hashable implement?

　　A. Java.util.Map.

　　B. Java.util.List.

　　C. Java.util.Hashable.

　　D. Java.util.Collection.

　　Answer: A