JAVA认证历年真题：310-025精选题（39）

会计考友

310-025精选题（39）的具体内容如下：
; r* k9 Z3 V$ M, d/ l9 y; R163. Which of the following statements about Java's garbage collection are true? A. The garbage collector can be invoked explicitly using a Runtime object.
' a# \% x$ D, M. E: cB. The finalize method is always called before an object is garbage collected.
. \# R- u. \( S2 G+ v% JC. Any class that includes a finalize method should invoke its superclass' finalize method.
6 g- X4 ]' N$ }  O$ O& u% X+ {0 WD. Garbage collection behaviour is very predictable.
ABC.
, A& g  l9 H! [1 B$ u+ h5 ^2 M164. What line of code would begin execution of a thread named myThread?
+ K# n  G/ e7 r: |7 g! qAnswer:
myThread.start();
165. Which methods are required to implement the interface Runnable?
) \8 M: }: R1 j5 B9 ~4 ]5 K" hA.wait()
0 P( m6 V. |% R8 ?B.run()
5 w! m. c/ Q3 u6 \C.stop()
D.update()
. [" X, c) F7 K9 t7 R5 n6 vE.resume()
B.
3 M! ?( b/ S) m  q$ j1 B166. What class defines the wait() method?
. n5 d% T* s6 g. yAnswer:
- c+ ^6 ~! {: W. X% ]4 s4 l$ EObject.
' ~+ G  }# [/ U6 `for yield(), sleep(#), start(), run() it is Thread
3 U* R3 b# y" n& {/ x) zfor wait(), notify(), notifyAll() it is Object
7 ]" |6 F0 U3 D( A167. For what reasons might a thread stop execution?
A. A thread with higher priority began execution.
, l  m+ Z' e7 `& U6 ^4 K7 Y  WB. The thread's wait() method was invoked.
C. The thread invoked its yield() method.
! K- m) G" K! I8 AD. The thread's pause() method was invoked.
E. The thread's sleep() method was invoked.
ABCE.

会计考友

168. Which method below can change a String object, s ?
( B/ D& a. M; A. R0 z6 CA. equals( s )
B. substring( s )
7 j% N" C7 T0 O3 D9 aC. concat( s )
* @" k5 H3 \1 I: Z" {D. toUpperCase ( s )
E. none of the above will change s
- \9 ], P2 ~% j4 X5 o) O1 g3 yE.
169. If s1 is declared as:
String sl = "phenobarbital";
What will be the value of s2 after the following line of code:
String s2 = s1.substring( 3, 5 );
A. null
4 R1 \: D# m* _! `  |' kB. "eno"
* f* W1 G2 @3 t6 SC. "enoba"
2 `0 K) |' q9 l( a  N# vD. "no"
% X! Z3 c' h/ u6 _7 e6 uD.
170. What method(s) from the java.lang.Math class might method() be if the statement method(-4.4)== -4; is true.
A. round()
# ?  E/ }& o. CB. min()
C. trunc()
/ z7 q* w" P/ v  OD. abs()
E. floor()
1 M7 k; L7 d$ D! O7 ]7 TF. ceil()
AF.