java认证试题：Java认证模拟题及分析(2)

会计考友

　　which of the following statements are true?
. h$ n6 j. r' X1 F　　1) methods cannot be overriden to be more private
0 `9 y7 U: \6 U+ n9 m+ z$ e　　2) static methods cannot be overloaded
　　3) private methods cannot be overloaded
5 \* ?9 {: ?8 A4 _4 D  N8 K8 c- v　　4) an overloaded method cannot throw exceptions not checked in the base class
( F4 H, X( P8 i3 O7 G8 z' ?　　answer to question 16
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7 E; V! M+ A8 ?" `4 E" e0 @　　question 17)
　　what will happen if you attempt to compile and run the following code?
　　class base {}
/ v; C2 ]2 P2 C7 O　　class sub extends base {}
　　class sub2 extends base {}
　　public class cex{
3 q! m! D  c- h4 e　　public static void main(string argv[]){
1 y' o  [# k& O　　base b=new base();
1 U3 K4 K; L( y) f( L　　sub s=(sub) b;
. y7 g' Y2 g5 g# j1 W' u# l　　}
3 a$ {+ p: A0 K+ D　　}
8 e- H$ m% n- w, ?# t$ j7 h　　1) compile and run without error
　　2) compile time exception
# S1 {. w/ P  S3 t" {　　3) runtime exception
　　answer to question 17
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　　question 18)
　　which of the following statements are true?
, n; e9 L5 b/ B# _　　1) system.out.println( -1 %26gt;%26gt;%26gt; 2);will output a result larger than 10
7 n) Z+ C5 ?2 W5 a　　2) system.out.println( -1 %26gt;%26gt;%26gt; 2); will output a positive number

　　3) system.out.println( 2 %26gt;%26gt; 1); will output the number 1
8 G7 a- r" R  ]2 g　　4) system.out.println( 1 %26lt;%26lt;%26lt; 2); will output the number 4
　　answer to question 18

　　question 19)

会计考友

</p>　　what will happend when you attempt to compile and run the following code?
- o0 g: j$ I, N) L　　public class tux extends thread{
4 @+ }  N0 H$ T3 N* ^' o3 W　　static string sname = 'vandeleur';
9 d& I( ]5 H% }% f$ q　　public static void main(string argv[]){
　　tux t = new tux();
　　t.piggy(sname);
# l4 \5 Z' N$ [6 Q' Q) ]　　system.out.println(sname);
　　}
　　public void piggy(string sname){
- D8 m  O0 p7 K2 N( }- ^　　sname = sname + ' wiggy';
　　start();
　　}
　　public void run(){
　　for(int i=0;i %26lt; 4; i++){
　　sname = sname + ' ' + i;
　　}
9 Q, T  i% i! M; w- \9 D, O6 E9 @　　}
2 d) O5 u2 {: r$ Y( B5 ?' n# u　　}
6 x3 h4 s8 \, B# Z　　1) compile time error
　　2) compilation and output of 'vandeleur wiggy'
　　3) compilation and output of 'vandeleur wiggy 0 1 2 3'
5 q4 i6 k: T! O0 G　　4) compilation and probably output of 'vandeleur' but possible output of 'vandeleur 0 1 2 3'
　　answer to question 19
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　　question 20)
　　what will be displayed when you attempt to compile and run the following code
$ ~' e2 T" C) {2 i  A　　//code start