2011年JAVA认证模拟题第二阶段（6）

会计考友

　　Q16.What will happen when we try to compile the following code.
　　1. public void WhichArray( Object x ) {
, k6 L5 M) L( S$ S& H) u　　2. if( x instanceof int[] ) {
　　3. int[] n = (int[]) x ;
* }* q# E3 B2 R　　4. for( int i = 0 ; i < n.length ; i++ ){
6 c$ d; X* |3 B' o1 {+ {; ^　　5. System.out.println(“integers = “ + n );
8 \6 r! M$ }- Q　　6. ｝
　　7. ｝
8 }0 R, w; {. U, X　　8. if( x instanceof String[] ) {
　　9. System.out.println(“Array of
4 g$ {) c! P; L2 k　　Strings”);
. e0 A4 H% `2 E+ g　　10. ｝
　　11. ｝
　　a. The compiler objects to line 2 comparing an Object with an array.
  I5 u/ G5 |1 x3 y　　b. The compiler objects to line 3 casting an Object to an array of int primitives.
　　c. The compiler objects to line 7 comparing an Object to an array of Objects.
　　d. It compiles without error.
( \/ p9 I6 ~. K, @( i% d- V
7 z6 H$ }& Y. C　　Q17.Consider the following class

会计考友

</p>　　1. class Tester {
　　2. void test (int i) { System.out.println (“int version”); ｝
　　3. void test (String s) { System.out.println (“String version”); ｝
　　4.
. i0 ?- Z5 d3 Z+ z4 b　　5. public static void main (String args[]) {
　　6. Tester c = new Tester ();
- ?2 N- h% D  ~' |3 D/ `　　7. char ch = 'p';
% I/ w/ S0 i/ J: ^8 a" Q　　8. c.test (ch);
1 T9 o3 e/ p5 S" P　　9. ｝
/ D0 |. V5 N. W& F6 W　　10. ｝
8 C0 R, Z! y8 l5 s　　Which of the following statements below is true?(Choose one.)
　　a. Line 3 will not compile, because void methods cannot be overridden.
　　b. Line 8 will not compile, because there is no conversion of test() that takes a char argument.
& n) r2 ^/ m+ `+ E( E  g! U　　c. The code will compile and produce the follwing output “int version”
) t- l  {" h; G& X　　d. The code will compile and produce the follwing output “String version”
1 R' ^. ]' h' O) F　　Q18.You are creating a ToolBase class which will be extended by other programmers. The ToolBase class contains a single abstract method, createTool. Which of the following statements are true?
' ]" G) L9 O# L& ?　　a. The ToolBase class must be declared abstract.
　　b. Classes extending ToolBase must not be declared abstract.
& L8 [5 s5 \7 r& d( y% i& m, m　　c. The ToolBase class must not be declared final.
　　d. The following variable declaration is illegal in any context “ToolBase myTB;”
& C- H* c8 }5 J) B/ w　　16. d
　　17. c
　　18. ac