JAVA认证历年真题：310-025精选题（13）

会计考友

37. What would be the result of attempting to compile and run the following piece of code?
public class Test {
" E* i5 ]) I  `( p6 {public static void main(String args[]){
int x;
5 M& M+ f, t$ k: a4 mSystem.out.println("Value is " + x);
}
* H) c& c& C; D* A9 q}
# @5 J5 F7 ~" ?7 P, E4 SA. The output "Value is 0" is printed.
2 E1 E: G2 ~: V; C1 K) P& H& Q3 m: c0 `B. An object of type NullPointerException is thrown.
C. An "illegal array declaration syntax" compiler error occurs.
6 K9 x* y  \7 u" j/ u0 FD. A "possible reference before assignment" compiler error occurs.
E. An object of type ArrayIndexOutOfBoundsException is thrown.
# f( T2 ]' s$ [% H5 _9 L( HD. Compiler says variable x might not have been initialized.
38. What should you use to position a Button within an application Frame so that the size of the Button is NOT affected by the Frame size?
/ J+ v2 C: S( b( @/ P0 [) ?+ S$ KA. a FlowLayout
. Z% J  i" ~8 i5 X8 Z' }) @: x/ rB. a GridLayout
C. the center area of a BorderLayout
D. the East or West area of a BorderLayout
E. The North or South area of a BorderLayout
A.
* Z; B2 B' E) M1 L# a  C* tFor the following six questions you will be presented with a picture in the real test, showing the relationship and quite long text, but don't be afraid the questions are quite easy.
) I+ }' x2 t8 r; H, e* m3 O39. We have the following organization of classes.
: {+ ~: Z$ H# r! D6 iclass Parent {}
7 R% }# H9 |! N  R* jclass DerivedOne extends Parent {}
class DerivedTwo extends Parent {}
Which of the following statements is correct for the following expression?
Parent p = new Parent();
% R" y5 Y/ P0 f3 ?( BDerivedOne d1 = new DerivedOne();
DerivedTwo d2 = new DerivedTwo();
, x& ^1 `8 R, z3 D1 W5 H" ^p = d1;
A. Illegal both at compile and runtime.
6 w, r* I( r. Y. T2 Z! q% [B. Legal at compile time, but may fail at runtime.
C. Legal at both compile and runtime.
" N2 M1 q. E' T) K. i# O( V5 pD. ....
( B$ T9 q) G: T  {3 U" YE. ....
! @! C+ @  m3 _- XC.