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 {
- Q( s( |, k. @- c12. public static void main(String [] args) { . U$ C+ Q c; j1 U- p! A
13. int x =5; - V" w' l, _0 b* z/ n1 ]3 X
14. boolean b1 = true;
* \4 v/ l9 R$ n; t0 V7 y* T+ r15. boolean b2 = false; * T. S3 y& g: |. n4 {# k; ~& o+ n: F
17.if((x==4) && !b2)
6 D0 @+ ]; E' r: R' K18. System.out.print(”l “);
; b# x% T( `$ J0 C F3 F# v19. System.out.print(”2 “); * R1 A3 C4 Q5 x: z E" |9 {, P) ^
20. if ((b2 = true) && b1)
/ P1 V/ _, p2 ?# v21. System.out.print(”3 “); 6 w* |2 l- W) O* c7 S# a
22. }
* P! m* ]# D$ D! C4 p23. } 3 ` q, W2 M9 k! K' [
What is the result? % R. U1 s" |3 z
A. 2
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C. 1 2 & K( H F+ I9 C' R
D. 2 3
! `6 T0 }' D& t# p* V5 YE. 1 2 3 + ]$ N: K- \' c
F. Compilation fails.
. o- q+ D) y( }! p' \& @G. Au exceptional is thrown at runtime. Question 2 Assume that country is set for each class. Given: 10. public class Money { ( l/ w& |9 }# K$ A: k( Q5 E# z
11. private String country, name;
, y$ `% Y6 l9 `4 {12. public String getCountry() { return country; } 0 r# y4 d/ |8 |8 Q* @: t
13.} and: 24. class Yen extends Money {
$ M% s O" t4 I( D9 K# \! T25. public String getCountry() { return super.country; } ; C3 @! m% E/ ?. P/ I7 Y6 X
26. } 9 B' t4 P0 I; x
27.
4 \0 B4 \4 E4 \3 e# K/ r) w28. class Euro extends Money { : l# L c3 u6 _- ]+ P9 G% i9 {
29. public String getCountry(String timeZone) { ) W3 z& P6 I+ C& |
30. return super.getCountry(); ' B2 ^ [# _7 y* _$ }4 `3 ]
31. }
- P I" g+ e/ s. C" n C32. }
/ v0 m/ k! b9 QWhich two are correct? (Choose two.) A. Yen returns correct values.
( U3 f, b1 ~% D n7 {8 H) b; d2 zB. Euro returns correct values.
s& P7 k( A9 d" j) g) O: qC. An exception is thrown at runtime. 9 M. ~0 l) i& `: L/ u- c
D. Yen and Euro both return correct values.
" ~( V1 g3 j1 |9 KE. Compilation fails because of an error at line 25.
# b! L; g' ^5 n3 J' LF. Compilation fails because of an error at line 30. Question 3 Given: 1. class TestA {
+ i6 ~5 y6 I- K( k' J* C# ]2. public void start() { System.out.println(”TestA”); }
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4. public class TestB extends TestA { 3 w3 d) |3 r- ], @$ o
5. public void start() { System.out.println(”TestB”); }
# x/ N( K5 s& x. j4 ^* s5 V% r6. public static void main(String[] args) { / ]4 @! p$ E+ P' G$ e
7. ((TestA)new TestB()).start();
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9. }
d n2 j6 V+ Z/ n% R+ k/ \% JWhat is the result? A. TestA
! {9 T, w% X7 G0 }9 |, ]7 xB. TestB 6 o/ p6 g9 L3 G9 X
C. Compilation fails. , P/ p1 | m8 O2 t) Z9 s
D. An exception is thrown at runtime. Question 4 Given: 11. public static void main(String[] args) {
' W0 A; F5 _6 R' I4 e12. String str = “null’;
7 p) L B" [+ d1 n3 p9 e9 W13. if (str == null) {
) w* g3 o+ V1 ?: O4 @14. System.out.println(”null”); 4 b; z |1 |2 S7 }
15. } else (str.length() == 0) {
) Y8 @7 b; H( y! D* P2 `16. System.out.println(”zero”); ; C4 U: q! X @8 P( I4 V$ `
17. } else { % w6 v' P" n, t2 Z2 J% x. c' h0 n% Y
18. System.out.println(”some”); # i8 M- W7 {4 M) K
19. }
, H: T, n4 x- H/ o20. }
4 G6 z0 ]) G& d% _# _‘What is the result? A. null
9 n! V) C9 B3 ~B. zero
% K+ d- j2 N5 W+ o1 _+ ZC. some
% V9 f+ Z# ^. s& ^D. Compilation fails. 1 G& Q2 j9 \1 Y# B; G
E. An exception is thrown at runtime. Question 5 Given: 33. try {
% P7 ~8 Q5 m$ D5 T8 q+ u, Y34. // some code here
, B* X. |; `" i1 S& Q3 a35. } catch (NullPointerException e1) {
a. W1 |4 J1 S$ w2 j3 `36. System.out.print(”a”);
5 b- f6 _+ X5 z: F# D37. } catch (RuntimeException e2) { 6 F( h9 z+ |" e( ^
38. System.out.print(”b”); % ?( e0 Y R$ x. z. D. u
39. } finally { ) x5 P0 ~( J& ~; {' @& ]
40. System.out.print(”c”); ( C( L* z2 ~1 v+ o v" \# R
41. } 0 q. X2 @" S5 P/ m( ` V& v. ?+ V
What is the result if a NullPointerException occurs on line 34?
9 b) m% a$ \9 B7 D6 u, j, CA. c
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F. abc Question 6 Given this method in a class: 21. public String toString() {
+ _8 s/ [) n" S2 p1 e22. StringBuffer buffer = new StringBuffer(); 1 d( ^' p4 F; [$ V& V {" ^" v
23. buffer.append(’<’);
8 |; p$ P I. F24. buffer.append(this.name); |6 ? k3 O- K# x; W
25. buffer.append(’>’);
$ I* s- h9 {. \) w4 M26. return buffer.toString();
- ]. v. b( h U! B% K2 |27. }
0 Y2 l/ A! Y* s4 T& ?: eWhich is true? A. This code is NOT thread-safe.
' K# T a% v- q: XB. The programmer can replace StringBuffer with StringBuilder with no
6 X- c6 J6 T( Q. b' J/ oother changes.
" V2 n: ^' s* d; r. RC. This code will perform well and converting the code to use 7 F Z; R. ~/ Z: z) N+ ~9 W
StringBuilder will not enhance the performance. * s# W9 B5 ^/ S* x3 `
D. This code will perform poorly. For better performance, the code
, a4 x2 _% R2 q7 Sshould be rewritten: return “<“+ this.name + “>”; Question 7 Given: 11. String test= “a1b2c3”; / [6 Y" U5 Z; u! Q7 r4 W
12. String[] tokens = test.split(”\\d”);
5 `5 D; o6 K' L0 Z13. for(String s: tokens) System.out.print(s +“ “); " ?3 }2 n* Q: S) V* S
What is the result? " N) N) h, C) [1 d) X4 v
A. a b c
) b" D: O, ^6 k3 M: B2 z# k! |B. 1 2 3
/ b( P- E/ s1 w+ b! c- X Y& ^C. a1b2c3 8 o; e+ u& _4 {+ K# C4 z
D. a1 b2 c3
0 h- D1 Y8 N7 y6 c/ M0 w: N" eE. Compilation fails.
! V, }( C0 {5 ?# eF. The code runs with no output.
+ A* ?, I; y0 X7 IG. 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
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