java软件工程师笔试题目(III) 规则: 1. 时间:40分钟 2. 个人独立完成,不能使用手机等上网上查询。如果被发现作弊,则零分。 3. 为了环保和节约纸张,请在答题卡上填写答案 一、不定项选择题(每题5分) Question 1 Given: 11. public class Test {
( A1 ~# w# r5 V! \& W) \12. public static void main(String [] args) { 2 O0 T: H+ }. G/ t* e
13. int x =5; 3 i! \# y8 o |" ~
14. boolean b1 = true; # L( h3 p6 |0 W# h+ D, V& M7 B% b
15. boolean b2 = false;
+ K5 |% K2 o7 p. W8 V5 \6 N" N17.if((x==4) && !b2)
5 U0 q8 a# l3 d' ^ j18. System.out.print(”l “); ( v7 f/ b+ f+ E& P
19. System.out.print(”2 “);
9 B" d6 Z* k# r. M0 v20. if ((b2 = true) && b1) 5 X/ Z" @8 { j7 |5 t, K
21. System.out.print(”3 “);
( y4 w: F: m$ b( R* F2 a, H22. }
& {0 k$ J- I9 D23. }
( A2 u# r' p8 L6 iWhat is the result?
$ o! c: }5 B1 ^; q4 b6 b1 }1 L: @A. 2
/ X% N4 o+ _9 r z! p( Q0 eB. 3
$ w5 I2 k S1 Z; e x0 TC. 1 2
' x4 Z7 U1 y! q. Y% Z7 QD. 2 3 ' v6 l* y3 C. {; w0 j; w
E. 1 2 3
W6 D- k; N2 V9 \ nF. Compilation fails. 5 D' [' C6 s9 k$ s1 c2 Y& R
G. Au exceptional is thrown at runtime. Question 2 Assume that country is set for each class. Given: 10. public class Money {
8 t9 T- p8 Y8 r' p8 O! u11. private String country, name; : C- F1 f$ M& C, F$ F) x) C! Y
12. public String getCountry() { return country; }
" F: U4 g5 B. E4 h13.} and: 24. class Yen extends Money { " {3 S0 C. y+ w1 l3 k
25. public String getCountry() { return super.country; } " I) F8 `5 v6 A
26. } + ?- W; j: J) Q+ |1 y
27. 7 G/ I# q! S2 s {3 P& J: q
28. class Euro extends Money { + S% T' v5 N: b6 z3 ?
29. public String getCountry(String timeZone) { ! g5 E6 Q1 ?# k) F6 F- V$ e
30. return super.getCountry(); 2 e3 u" ^0 o$ c
31. }
, V8 R$ Z1 h' y7 k3 s1 z3 Z32. } . G7 V$ b7 o' Z' n! y; r3 H' C6 H$ B
Which two are correct? (Choose two.) A. Yen returns correct values. ; s; c( r6 Z; v% K- H
B. Euro returns correct values. * r! R* I# h+ F: W% z
C. An exception is thrown at runtime. " L/ u. q3 l$ a6 Y* O5 l' Z
D. Yen and Euro both return correct values.
+ U7 i2 b" I2 W) wE. Compilation fails because of an error at line 25. - z3 O: x; t Q
F. Compilation fails because of an error at line 30. Question 3 Given: 1. class TestA {
& {5 t: ~6 \2 `; q2. public void start() { System.out.println(”TestA”); } 1 d" S9 S! ]; M, b2 T
3. } + l4 H$ \) O% K1 H" t. p$ I" n% {
4. public class TestB extends TestA { ( c: e' H% F# i/ y; h
5. public void start() { System.out.println(”TestB”); } . ~4 z5 U7 t* B$ Y
6. public static void main(String[] args) {
9 H$ {$ [( j1 d% D; U# [7. ((TestA)new TestB()).start(); 5 r$ n# y* o W* }6 J/ K
8. }
+ E: p. A& C, ]9. }
; o# W O/ \0 e2 hWhat is the result? A. TestA ( U- M0 L) q1 k1 R# x% _" @
B. TestB ' ` M! d4 f/ V# f& o# ^
C. Compilation fails. % b% w0 m% }* w `
D. An exception is thrown at runtime. Question 4 Given: 11. public static void main(String[] args) {
7 I& b4 h- s4 D9 R4 v) U12. String str = “null’;
) X/ L; d, n3 p13. if (str == null) { ; {0 O6 u+ a6 |' V4 T
14. System.out.println(”null”);
) v6 H5 N$ |* M9 j" l$ t15. } else (str.length() == 0) {
8 w& z) @, x; W8 @16. System.out.println(”zero”);
) ^0 B. y. ^8 O& R: ?/ A# I17. } else {
* M# A. x; m) X$ c3 K( x8 _/ ]5 J- ]18. System.out.println(”some”); 1 X) X; }. U5 a% Z$ R5 ?# ?& C$ O
19. } , _4 q b+ I$ r$ i& q0 I: y0 ]
20. }
. R k; Q) s. Z5 R+ p‘What is the result? A. null
6 a) U/ Y. A) Q+ ~9 _$ i3 xB. zero
' |; h1 r& B* R1 T: c1 nC. some
' c3 w; X7 `2 ?: y4 u: U8 H; }1 gD. Compilation fails.
7 y ?5 Q d, g: J) o+ DE. An exception is thrown at runtime. Question 5 Given: 33. try {
5 i: @1 l( x3 a6 ^- t34. // some code here / h7 D* z3 X4 M
35. } catch (NullPointerException e1) {
6 G' Q1 x* p/ d: n4 @# n0 x- l* h/ |36. System.out.print(”a”); ' V6 T& H8 Q; }
37. } catch (RuntimeException e2) { p4 x7 w0 d3 r) i3 u
38. System.out.print(”b”);
% \' ]( X8 ~/ W) Z4 u5 j39. } finally {
~# `( i; |. ~! s40. System.out.print(”c”); $ C( _5 ? P j( v" l! J
41. } ! z, {$ m& X/ \5 N& U
What is the result if a NullPointerException occurs on line 34? 5 I4 k0 U& a' ^7 v# E
A. c & Q# `$ r$ ~* F# J1 O
B. a . Y, J6 d w: _# x
C. ab 4 Y, b' l: E8 J% d% q4 A: b) H
D. ac * ?5 e5 J A2 \0 {: A
E. bc
' c. B, w9 C$ ~" x& R; Q+ MF. abc Question 6 Given this method in a class: 21. public String toString() {
- T) R+ c. v( h3 Z22. StringBuffer buffer = new StringBuffer();
; [ e' {6 M# v/ t/ R+ ^23. buffer.append(’<’); ' U, x6 h: l2 F5 b( y+ `
24. buffer.append(this.name);
4 J+ J `/ ^" t+ m25. buffer.append(’>’); # |% c; ]4 I8 {8 c4 p% n
26. return buffer.toString(); , m5 @+ P0 A0 i+ L
27. } 3 G% [* L0 m+ {6 p
Which is true? A. This code is NOT thread-safe. : n" n8 a$ v5 H* h" Q
B. The programmer can replace StringBuffer with StringBuilder with no 8 {. E6 a# a0 P
other changes.
0 J5 k* @5 y+ x9 d: q; \C. This code will perform well and converting the code to use
& w3 c; k) q4 v6 D8 E! pStringBuilder will not enhance the performance.
$ Q I& ^5 m. E4 b( ~+ G1 {8 C iD. This code will perform poorly. For better performance, the code 4 r3 V& u: D7 J& w6 n' u
should be rewritten: return “<“+ this.name + “>”; Question 7 Given: 11. String test= “a1b2c3”; a7 P5 G: \7 c9 E+ ^2 E
12. String[] tokens = test.split(”\\d”); " H) l$ G4 F3 \( X
13. for(String s: tokens) System.out.print(s +“ “); $ E6 w9 I+ p' ~* D. b' x" g
What is the result? % x/ F* g7 `; Q' [: s
A. a b c
. F- R2 Z) b3 w7 N! f- }B. 1 2 3
" H, E( c6 O' V- M8 A2 p7 D% A# \C. a1b2c3 # T X) T, D; T. Q3 r; z
D. a1 b2 c3 / J$ k- x( y" S4 t4 _
E. Compilation fails. $ N& {( w: H, H N
F. The code runs with no output. ) Y: C- ~; F q! Z p
G. An exception is thrown at runtime. Question 8 Question 9 Question 10 请选择同向的图形: Question 11 Question 12 表USER_INFO的结构如下: 下面那些选项可以插入一行到该表中: A、INSERT INTO USER_INFO(USER_INFO_ID, USER_NAME, PASSWORD) VALUES(null,'BQ','password'); B、INSERT INTO USER_INFO VALUES('helloword_id','BQ','password'); C、INSERT INTO USER_INFO(USER_INFO_ID) VALUES('helloword_id'); D、INSERT INTO USER_INFO(USER_INFO_ID, USER_NAME, PASSWORD) VALUES('helloword_id','BQ','password'); Question 13 下面关于视图说法正确的是: A、一个视图可以作为只读被创建。 B、一个视图可以用来连接两个或者更多的表而创建。 C、一个视图在select语句中不能有一个order by 语句。 D、一个视图在select语句中不能同group by 语句一起创建。 E、一个视图必须在select语句中为列名定义别名。 Question 14 EMPLOYEES表数据如下: 选择下面正确的选项: A、SELECT * FROM EMPLOYEES WHERE SALARY>(SELECT MIN(SALARY) FROM EMPLOYEES GROUP BY DEPARTMENT); B、SELECT * FROM EMPLOYEES WHERE SALARY>(SELECT MIN(SALARY) FROM EMPLOYEES GROUP BY DEPARTMENT); C、SELECT * FROM EMPLOYEES WHERE SALARY>(SELECT MIN(SALARY) FROM EMPLOYEES); D、SELECT * FROM EMPLOYEES WHERE SALARY>ALL(SELECT SALARY FROM EMPLOYEES); Question 15 STUDENTS表为空表,添加主键STUDENT_ID列,那个选项能完成这个任务: A、ALTER TABLE STUDENTS ADD PRIMARY KEY STUDENT_ID; B、ALTER TABLE STUDENTS ADD CONSTRAINT PRIMARY KEY (STUDENT_ID); C、ALTER TABLE STUDENTS ADD CONSTRAINT STUD_ID_KEY PRIMARY KEY (STUDENT_ID); D、ALTER TABLE STUDENTS ADD CONSTRAINT STUD_ID_KEY PRIMARY KEY STUDENT_ID; Question 16 一个学生只能就读于一个班级,而一个班级可以同时容纳多个学生,学生与班级之间是()的关系。 A、一对一 B、一对多 C、 多对一 D、多对多 % x' l8 a+ R2 o# D& {' e! `
|