57 
What is the result?
(A) Canada
(B) null Canada
(C) Canada null
(D) Canada Canada
(E) Compilation fails due to an error on line 26. 

(AB) Compilation fails due to an error on line 29.

51 Which statement is true about the classes and interfaces? (A) Compilation will succeed for all classes and interfaces. (B) Compilation of class C will fail because of an error in line 2. (C) Compilation of class C will fail because of an error in line 6. (D) Compilation of class AImpl will fail because of an error in line 2.

54 What can directly access and change the value of the variable name?(A) any class (B) only the Target class (C) any class in the test package (D) any class that extends Target

55 What is the result?(A) 0, 0, 0 (B) 150, 60, 0 (C) Compilation fails. (D) 150, 150, 150 (E) An exception is thrown at runtime.

56 Which is true?(A) if line 10 is removed, the compilation succeeds. (B) if line 11 is removed, the compilation succeeds. (C) if line 12 is removed, the compilation succeeds. (D) if line 13 is removed, the compilation succeeds. (E) More than one line must be removed for compilation to succeed.

58 Which code, inserted at line 16, will cause a java.lang.ClassCastException? (A) Alpha a = x; (B) Foo f = (Delta)x; (C) Foo f = (Alpha)x; (D) Beta b = (Beta)(Alpha)x;

59 Assume the current directory is bigProject, what it the result? (A) If the compile is successful, Utils.class is added to the source directory. (B) The compiler returns an invalid flag error. (C) If the compile is successful, Utils.class is added to the classes directory. (D) If the compile is successful, Utils.class is added to the bigProject directory.

複選題60 And MainClass exists in the /apps/com/company/application directory. Assume the CLASSPATH environment variable is set to "." (current directory). Which two java commands entered at the command line will run MainClass? (Choose two.) (A) java MainClass if run from the /apps directory (B) java com.company.application.MainClass if run from the /apps directory (C) java -classpath /apps com.company.application.MainClass if run from any directory (D) java-classpath . MainClass if run from the /apps/com/company/application directory (E) java -classpath /apps/com/company/application:. MainClass if run from the /apps directory (AB) java com.company.application.MainClass if run from the /apps/com/company/application directory

61 If both classes are in the correct directories for their packages, and the Mammal class correctly defines the findSalmon() method, which change allows this code to compile? (A) add import animals. mammals.*; at line 2 in Salmon.java (B) add import animals.fish.*; at line 2 in GrizzlyBearjava (C) add import animals.fish.Salmon.*; at line 2 in GrizzlyBear.java (D) add import animals. mammals.GrizzlyBear*; at line 2 in Salmon.java

62 What is the result? (A) b 3 (B) b 8 (C) b 13 (D) f 3 (E) f 8 (AB) f 13 (AC) Compilation fails, (AD) An exception is thrown at runtime.

63 Which three are valid? (Choose three.)  1. p0 = p1;  2. p1 = p2,  3. p2 = p4;  4. p2 = (ClassC)p1;  5. p1 = (ClassB)p3;  6. p2 = (ClassC)p4; (A) 123 (B) 126 (C) 235 (D) 156