2011年JAVA认证模拟题第二阶段（27）

会计考友

　　Q79.What is the result of attempting to compile the following program
　　1. public class Test {
　　2. public void method(StringBuffer sb) {
　　3. System.out.println(“StringBuffer Verion”);
　　4. ｝
　　5. public void method(String s) {
　　6. System.out.println(“String Version”);
　　7. ｝
  g; e$ K' w/ W  e( g　　8. public static void main(String args[]) {
　　9. Test test = new Test();
　　10. test.method(null);
　　11. ｝
　　12. ｝
2 Z' [  n) o. f- Z　　Select one correct answer
　　a. The code does not compile.
& F4 P$ G2 Z; ?- M# ~/ J( @7 V　　b. The code compiles correctly and shows
) i  }7 U; Z( L( H5 V' S& T　　c. The code compiles correctly and shows “String Version”.
　　d. The code throws an Exception at Runtime. NullPointerException in the 2nd line of the main method.
9 r  T4 n/ {" C/ L0 n　　Q80.What is the requirement of the class which implements the following Interface
　　1. public interface Test {
; ?6 j3 f. ]# P　　2. void someMethod();
　　3. ｝
" ?; X1 U2 X7 t, l8 g　　Select all correct answers
　　a. Should have someMethod which must be necessarily declared as public.
　　b. Should have someMethod which could be “friendly” or public
) L/ G- v8 o3 b6 ?# I% @! `( Y) q% R　　c. Should have someMethod which should not throw any checked exceptions.
: d9 ?$ v! h; U) [! h' I6 y3 n8 o　　d. Should have someMethod which cannot be sychronized as sychronized is not in the signature of the interface definition.
6 m3 Y; p* W2 ^4 d' B, C　　Q81.What is the result of attempting to compile and run the following program?
9 b) ]+ ?9 M3 t. i, r　　1. public class AStringQuestion {
" h4 p1 }- D. w. y: D: k　　2. static String s1;
9 _" z& D' t) \, O8 G' p　　3. static String s2;
; K1 a* S  j! k3 o　　4. public static void main(String args[]) {
　　5. s2 = s1+s2;
' D/ u/ b) R1 v# h8 N/ e- |  e, e　　6. System.out.println(s2);
& O, W1 |' A- U, Z- _　　7. ｝
" R# K( h) @! S2 U& \* ~　　8. ｝
　　[Select one correct answer]
% A" c% g  n8 O; q" w9 d, G/ n　　a. Will cause a compilation error. “StringBuffer Version”.
　　b. Runtime Execption -
" Q- L, V4 g$ M) C　　c. Will compile successfully and print “nullnull” on the screen.
　　d. Will compile successfully and print an empty line on the screen.
# m7 Y/ M; N& H+ x& @　　79. a
1 H2 t2 O6 D% _( d1 k: n* Y. s' _) `　　80. ac
　　81. c