2011年JAVA认证模拟题（47）

会计考友

　　Q139 What is the output displayed by the following program?
; w6 v* H: W) i9 |　　class Question {
7 K1 V5 g9 f$ E. H; v　　public static void main (String[] args)
　　{
　　String s1 = “ab”;
1 _; ^, z/ h. _" `　　String s2 = “abcd”;
% ~" U% D2 G4 b( u0 j, a　　String s3 = “cd”
: k0 g2 [4 P" t+ S2 G5 U　　String s4 = s1 + s3;
　　s1 = s4;
　　System.out.print(“s1 “ + (( s1== s2) ?
　　“==” ： “!=”) + “ s2”);
" I) J! i2 s9 y/ Y9 E/ _0 B　　｝
　　｝
" V: N% h& J3 m: {, s) R　　A s1 == s2
( M# @" U; o) [8 E/ _; Y8 I  J7 t　　B s1 != s2
2 E- i2 ?( |% z9 `, v4 R' z/ g　　C s1
1 h( |! ~  `8 e& }$ A& O　　D s1 == “abcd”
　　Q140 Which of the following are true about constructors?
, e1 M( a4 S. B4 r/ ^. p- P; P: ^　　A A class inherits its constructors from its parent.
　　B The compiler supplies a default constructor if no constructors are
' C9 R( u+ C; h9 h9 W　　provided for a class.
1 u/ o5 A# s5 v2 U2 n, o　　C All constructors have a void return type.
# i# a* a2 z# `5 v/ q　　D A constructor may throw an exception.
. N: E" O. `6 m　　Q141 Which of the following are primitive types?
. G7 V& H2 r& n. c6 E) s$ Z　　A byte
: j# i7 C* l' u" ?　　B String
　　C integer
　　D Float
　　Q139 B
1 [& y& C9 N+ S( d　　Q140 BD
7 |+ x3 h# i; R9 L6 s' F7 O　　Q141 A