10. public class SuperCaic { 11. protected static int multiply(int a, int b) { return a * b; } 12. } and: 20. public class SubCalc extends SuperCalc { 21. public static int multiply(int a, int b) { 22. int c = super.multiply(a, b); 23. return c; 24. } 25. } and: 30. SubCalc sc = new SubCalc(); 31. System.out.println(sc.multiply(3,4)); 32. System.out.println(SubCalc.multiply(2,2)); What is the result?()
第1题:
10. public class ClassA { 11. public void count(int i) { 12. count(++i); 13. } 14. } And: 20. ClassA a = new ClassA(); 21. a.count(3); Which exception or error should be thrown by the virtual machine?()
第2题:
1. public class A { 2. public void doit() { 3. } 4. public String doit() { 5. return “a”; 6. } 7. public double doit(int x) { 8. return 1.0; 9. } 10.} What is the result?()
第3题:
A. 10. 10. 13.0
B. 10. 10. 0.0
C. 10. 13.15
D. 10. 0. 0.0
第4题:
Cat is-a Jumper
Cat is-a Animal
Dog is-a Jumper
Dog is-a Animal
Beagle has-a Jumper
Cat has-a Animal
Beagle has-a Tail
第5题:
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; 10. return o; 9. } 10. } When is the float object created in line 3, eligible for garbage collection?()
第6题:
1. public class Outer{ 2. public void someOuterMethod() { 3. // Line 3 4. } 5. public class Inner{} 6. public static void main( String[]argv ) { 7. Outer o = new Outer(); 8. // Line 8 9. } 10. } Which instantiates an instance of Inner?()
第7题:
1. public class X { 2. public static void main (String[]args) { 3. int [] a = new int [1] 4. modify(a); 5. System.out.printIn(a[0]); 6. } 7. 8. public static void modify (int[] a) { 9. a[0] ++; 10. } 11. } What is the result?()
第8题:
A.
B.
C.
D.
E.
F.
第9题:
Just after line 5.
Just after line 6.
Just after line 7.
Just after line 8(that is, as the method returns).
第10题:
An exception is thrown at runtime.
Compilation fails because of an error in line 7.
Compilation fails because of an error in line 4.
Compilation succeeds and no runtime errors with class A occur.