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 { 2 j$ v" `6 _( K) y
12. public static void main(String [] args) { ( w$ b6 ~( t" T5 a$ y$ a
13. int x =5; 8 z: \: G; f4 D- J' b# S( k$ D. F, V
14. boolean b1 = true; I, _: D9 B5 C
15. boolean b2 = false; 5 D$ [: M/ J! X8 |5 M
17.if((x==4) && !b2)
0 n5 v* \8 s2 N18. System.out.print(”l “);
8 j' { I( y" }; G19. System.out.print(”2 “);
( {0 b8 p/ n- [8 b! ]8 w20. if ((b2 = true) && b1)
6 ]) p' X1 V j% b21. System.out.print(”3 “);
& ~0 @/ @0 B+ s2 o22. } 0 G! D/ Z1 i. ~: ^
23. }
, b/ L5 s( U2 W$ ~5 }$ x kWhat is the result? & X" F2 C6 m3 I$ u$ U! L( B4 w
A. 2 . q$ H* ^/ q, W0 R) z7 J; c
B. 3
( l' h" C( \! S. g# `- A( D8 kC. 1 2
8 R! B: `) L- |D. 2 3
0 u1 B$ _! Z1 ^& bE. 1 2 3
8 x0 a" e4 ]& dF. Compilation fails. 9 U6 z9 e3 y' w2 s5 E+ A
G. Au exceptional is thrown at runtime. Question 2 Assume that country is set for each class. Given: 10. public class Money {
. I4 i: |$ ?2 d2 C3 s7 D11. private String country, name;
9 B S b- f: G) @) E7 q' W12. public String getCountry() { return country; }
5 G# @* I0 S3 L9 a13.} and: 24. class Yen extends Money { 9 D4 X0 y" M5 L- ^* r2 {
25. public String getCountry() { return super.country; }
. I$ w9 X7 J; H, B26. }
& s* G, }& C7 j( `8 `, ^* a. v27.
7 H( F1 U2 }" z3 q28. class Euro extends Money {
& t: ^; l# P/ }8 `29. public String getCountry(String timeZone) {
/ ?" `9 _( d, c8 p+ V: j+ ]) p+ l# h30. return super.getCountry(); # ? B: e! C2 ^; z
31. }
% Q$ d2 d9 b6 @6 h* S6 Q% h; H. p, x32. }
4 A f5 M" m" vWhich two are correct? (Choose two.) A. Yen returns correct values.
# }3 m- K: X; L( \6 D* i4 jB. Euro returns correct values. ! Q- j$ s2 ?4 X- x1 e( {
C. An exception is thrown at runtime.
. J2 G" r/ _4 m$ v9 l: BD. Yen and Euro both return correct values. 9 m$ P( s- N, x
E. Compilation fails because of an error at line 25.
- o6 J; i h# E1 {9 `F. Compilation fails because of an error at line 30. Question 3 Given: 1. class TestA {
2 w% m* c# W9 }( y2. public void start() { System.out.println(”TestA”); }
% I3 T% @+ u. T$ f/ L" G4 g* B) o$ T3. }
' G+ D' w$ M- K7 ]. W# U4. public class TestB extends TestA { 8 R' Z$ u4 C8 u: K
5. public void start() { System.out.println(”TestB”); } $ L% }1 c% S& t) Y Q( \
6. public static void main(String[] args) { + N! c l. w, j6 E+ _
7. ((TestA)new TestB()).start(); ( E$ @9 J; u1 A+ N7 m9 z2 Q3 w
8. }
6 Y/ i. j) n- `- W9. }
/ o2 T N5 G" V" k" XWhat is the result? A. TestA 5 d- B* ~2 T" z" @) c* _
B. TestB + g' L! }6 T5 ~( D- x! Z
C. Compilation fails. m1 s3 N; k" U8 O* E
D. An exception is thrown at runtime. Question 4 Given: 11. public static void main(String[] args) {
& P) i2 k( @6 T/ V: \4 `" J12. String str = “null’; / i+ N8 |! r' R* O5 `. N) q1 I6 M: c
13. if (str == null) { 5 {: o; F k+ L+ g% p
14. System.out.println(”null”);
0 d' Z+ K4 w- l15. } else (str.length() == 0) { 1 u2 L7 a' O! W5 y# O }
16. System.out.println(”zero”);
; J( \0 _; q4 b# y: l x" A, `17. } else { $ Q. l) r' j* W2 C- A7 j1 x' X
18. System.out.println(”some”);
2 o" O4 e& P! y8 l19. } % c7 Q) T( I0 G9 y7 e# o8 C
20. }
8 Z8 c8 p/ R" C3 q( l1 k‘What is the result? A. null
7 V. M5 Z# o# P" G- zB. zero - f/ H( w( v" [) [! ?8 k
C. some 9 ^4 a# g0 i7 A1 w
D. Compilation fails. 0 l6 `! b$ b# T- W1 M) Y
E. An exception is thrown at runtime. Question 5 Given: 33. try { 8 \0 ^" n( Y) Y" | e. P/ @
34. // some code here
$ B; R0 R9 R: J# }" p* y7 E* J35. } catch (NullPointerException e1) { ) g6 n; K3 r- S; H$ T; k, @
36. System.out.print(”a”);
' Z8 I% i7 g2 H! Q: U7 O, b5 U37. } catch (RuntimeException e2) {
! V$ b' U; o2 R. f38. System.out.print(”b”);
& g' v; a) h/ M8 o, a6 M39. } finally {
% `" B9 Z5 d' u$ ~40. System.out.print(”c”);
- ? G7 n- `! e m41. } / a, H. e- S0 B9 ^! W# e
What is the result if a NullPointerException occurs on line 34? 2 q% u! f A- n5 l
A. c
8 s, E% v- T. n4 Z0 yB. a
2 q( R$ u0 n3 XC. ab 2 ~. r, q7 ?$ ?6 `/ `# \: z, h
D. ac
+ X. }( C6 h0 ?4 HE. bc
j% e2 D) G s* p3 NF. abc Question 6 Given this method in a class: 21. public String toString() { 2 G) D2 D8 N. U$ q( c
22. StringBuffer buffer = new StringBuffer(); % E, r( r5 f4 T `8 ^) @5 O9 K5 d
23. buffer.append(’<’);
" h) x& ~; q) P0 K2 @24. buffer.append(this.name);
/ o2 K8 n) v3 r25. buffer.append(’>’);
1 v2 O$ J& w: W3 G$ A26. return buffer.toString();
: p k" q7 n: `& }% S" l27. }
- _" R/ }, G/ A7 \1 }7 ZWhich is true? A. This code is NOT thread-safe.
* k7 l u6 {; o- ^* W* P, RB. The programmer can replace StringBuffer with StringBuilder with no
3 {# h$ Y4 F; r! R# Q6 tother changes.
5 B- z* K9 v7 A7 ^7 U- YC. This code will perform well and converting the code to use - z/ Y% S2 X- _2 N+ \' ^
StringBuilder will not enhance the performance. ! [1 l ?0 x3 \% A8 K
D. This code will perform poorly. For better performance, the code $ ?0 |5 o. ^- e/ J
should be rewritten: return “<“+ this.name + “>”; Question 7 Given: 11. String test= “a1b2c3”; k4 ^. w+ i, q8 i4 J
12. String[] tokens = test.split(”\\d”); - R6 s5 {. }6 H' t7 E
13. for(String s: tokens) System.out.print(s +“ “); ! m2 V9 o m; G( x/ s( v7 Q
What is the result?
6 i _0 u- R5 v# Q6 oA. a b c 6 p4 s0 Y9 w5 T& U( v$ I
B. 1 2 3 ) u: n- s& K$ @1 k
C. a1b2c3
5 J [9 L0 u, k7 ~9 AD. a1 b2 c3 & ^; X& P0 t9 Y. S! d
E. Compilation fails. % o" ?! r2 X7 K& ~* Y( u
F. The code runs with no output. , H; j! G# t+ g5 `8 G0 {
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 " ~ ]' N( J7 R6 t( w2 X
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