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 { " h6 F! t+ |, u2 k8 s
12. public static void main(String [] args) {
. R3 p' Z* ]& g p k13. int x =5;
8 o D6 P4 u( ?1 \% ?7 X14. boolean b1 = true;
0 G. M9 @$ E2 I15. boolean b2 = false; 6 G. ?/ a/ N h- l2 h8 I
17.if((x==4) && !b2) ' J1 v6 m+ z3 {
18. System.out.print(”l “);
8 Q6 u- Y* c% X: E5 N19. System.out.print(”2 “); . z9 ^2 H3 |0 e! v i' H
20. if ((b2 = true) && b1)
" S' l$ m& b& E* L8 m! h# E. y3 s4 m21. System.out.print(”3 “);
' h i" H3 w# ]' G: O22. }
/ N! M. d: R" g: Z( y23. }
* `! B/ ~1 i0 `7 ]2 qWhat is the result? ; c, H' t& d! {
A. 2
# h. Z/ i" H; B3 l; v; GB. 3 5 S6 H; u" w4 W1 k. A
C. 1 2 [5 l) {5 t& f
D. 2 3 - N- q3 r% N) g! E5 c
E. 1 2 3
5 v: ~+ z% b+ E3 U" fF. Compilation fails.
, D& W1 @/ t- c, JG. Au exceptional is thrown at runtime. Question 2 Assume that country is set for each class. Given: 10. public class Money { , U" ?! y1 n$ D; D% k* A9 i: \
11. private String country, name;
8 [8 |" |3 W; Z% [; E `12. public String getCountry() { return country; }
8 U0 U( {' u! F& h/ k' g13.} and: 24. class Yen extends Money { 8 m/ q0 c5 D8 d. D
25. public String getCountry() { return super.country; } & [4 T0 D! J) u Q4 x
26. } * v& _ B6 b: ]4 A2 m. ?' ~/ Q
27. 4 ~1 h* n" e7 k) I- H' G1 U
28. class Euro extends Money {
# N7 y: B& o3 v/ o29. public String getCountry(String timeZone) { ' {5 U) Y! q5 @. Y$ y1 y
30. return super.getCountry(); ! }' d8 c! q, n8 D- b# |. Q
31. } 8 \( A* u3 _2 H3 O/ V4 v
32. }
V' E/ m5 Q. V8 F' ?3 p. R/ tWhich two are correct? (Choose two.) A. Yen returns correct values. 9 V3 s6 C3 f3 Z) d) I1 G
B. Euro returns correct values.
$ K6 \2 O% ?( ]* ?% G" AC. An exception is thrown at runtime. 4 P) t+ P2 w" K2 s
D. Yen and Euro both return correct values.
* d$ F0 u4 ?" { FE. Compilation fails because of an error at line 25. 8 g9 X! @+ `$ Q
F. Compilation fails because of an error at line 30. Question 3 Given: 1. class TestA { , {. @3 _/ d: T4 c( W4 H
2. public void start() { System.out.println(”TestA”); }
% G# R9 T/ \5 r R% G7 u+ X3. }
6 f' Y0 M, f$ V4 ^$ Q7 X4. public class TestB extends TestA { 0 _9 n* e9 w P+ }8 }. t, q" x! T
5. public void start() { System.out.println(”TestB”); } * q A) l t! ~* ^& N$ A& G
6. public static void main(String[] args) { " Y7 J1 l" W$ {0 X: `% p/ z+ a
7. ((TestA)new TestB()).start();
. U2 M; l6 ~1 p1 r# I( K8. }
. P- T$ H+ e5 E4 D, a9. } # i7 N5 @, E! I: y7 E6 W1 [; m
What is the result? A. TestA 0 o7 P" Q( t+ \/ o9 D3 M& U; g
B. TestB . k4 h9 X" @* G* h0 G
C. Compilation fails. 2 }- L' L* d$ M& v9 H6 F: L
D. An exception is thrown at runtime. Question 4 Given: 11. public static void main(String[] args) {
# X0 ^0 g! s: H8 v8 X8 x6 M2 q) ?; B12. String str = “null’;
4 m2 `% B# e+ v- ]* _13. if (str == null) {
. g( f# D/ D* z14. System.out.println(”null”); 9 `2 k1 ~; K! ?4 k* v. T
15. } else (str.length() == 0) { , |6 k" @ s k( k# t7 e) M3 I. j
16. System.out.println(”zero”);
. z7 n: w" M! m17. } else {
$ P; ^1 t! p8 c( P4 ^9 z18. System.out.println(”some”); - H% P* i' l) G5 z/ ^
19. }
$ q% T% _4 o Y- f20. }
2 L O4 B2 m# A# }9 c‘What is the result? A. null
' {8 B) B8 J9 }B. zero
+ q- W7 F, \, F+ CC. some 6 _ ^1 b6 z1 j4 L! ]; ?" @
D. Compilation fails.
1 |( U% t! u1 ^% D; g# _! PE. An exception is thrown at runtime. Question 5 Given: 33. try {
, H1 w( R3 p+ q3 f2 |- L' v5 B3 l34. // some code here # z; B2 [ T- M; ?' H4 C
35. } catch (NullPointerException e1) { ]7 P4 h, B) ?% j3 m* M
36. System.out.print(”a”); 8 _: ?! _4 l B: [; U3 f% E
37. } catch (RuntimeException e2) {
6 c: k* E( H5 L# @* }- c38. System.out.print(”b”);
y5 b7 u* z: @39. } finally {
+ ]" |( Z c8 U40. System.out.print(”c”); 0 ]+ m4 N$ r5 z- G, m& c& |% R
41. } 4 Z" G: b- `# O$ ~; t( M
What is the result if a NullPointerException occurs on line 34?
. @0 r5 y. D+ UA. c X6 u7 J3 L8 |8 F( P
B. a % Y1 }; H9 [$ B8 ^9 s" v
C. ab " k% t0 Y- N8 M' x2 c! A
D. ac 1 T- d1 z+ e: |% K$ a
E. bc
* G/ U7 |/ j" N. NF. abc Question 6 Given this method in a class: 21. public String toString() { f( q+ `/ V$ ^5 {
22. StringBuffer buffer = new StringBuffer();
+ E* S9 r/ y+ o" G% i' L23. buffer.append(’<’); ' V4 U6 x/ f4 C
24. buffer.append(this.name); 1 @ Z0 e. C( b6 G& @; r
25. buffer.append(’>’);
; [8 ?( r I9 R$ Y N4 {26. return buffer.toString(); 6 u' V/ _4 \) o/ y3 E/ z
27. } 4 q& y J# r8 X% o5 V) {* W" _& b7 W
Which is true? A. This code is NOT thread-safe. : J( M& L% Z" V) g% I
B. The programmer can replace StringBuffer with StringBuilder with no
! G5 [1 y! E. y2 r" t3 T0 u) Rother changes.
" ?! t" W& A* ], I8 H+ G" NC. This code will perform well and converting the code to use ' K! f( I$ F0 p/ D0 A2 V; g
StringBuilder will not enhance the performance. ' j! ^. j' g& {, l
D. This code will perform poorly. For better performance, the code a0 x. i+ V: H/ F
should be rewritten: return “<“+ this.name + “>”; Question 7 Given: 11. String test= “a1b2c3”;
0 R& C8 G1 O* x/ y' H12. String[] tokens = test.split(”\\d”);
8 [+ D- ^: F( c2 p8 ^5 `$ q13. for(String s: tokens) System.out.print(s +“ “); " ?+ c2 x7 n# @, [" |9 n. U
What is the result?
2 }4 {( V4 m% D9 C7 a% ~A. a b c
' _4 q8 J$ j! s, B$ EB. 1 2 3 3 e: j3 z7 [0 d# D7 M5 [
C. a1b2c3 * @( q; h9 m8 ^9 R% z8 J& C
D. a1 b2 c3
9 A3 L- ~2 D Q6 O8 }# C+ K0 QE. Compilation fails. 8 _# e- H7 |* Y7 d5 B
F. The code runs with no output. & Q) N( [9 u2 D& b6 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 & G- E0 T" \0 m V8 f
|