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 {
: j4 I5 T! S9 ]5 X# d: E' \* f8 X12. public static void main(String [] args) {
' q# ?9 T3 q* U1 c% ]3 J13. int x =5; & X _6 {1 F9 m
14. boolean b1 = true; 6 t6 N4 ?) n, V
15. boolean b2 = false;
1 b) n$ D5 U! U( u$ u+ H$ d: ^0 h* l17.if((x==4) && !b2) ' ~( _& o/ v U1 D4 j/ g
18. System.out.print(”l “);
" ]2 |; Y7 ^9 f K" X: l P19. System.out.print(”2 “);
* d* i4 P! Q& x/ L20. if ((b2 = true) && b1) 7 `8 l4 ?* T: U, g) Y/ x
21. System.out.print(”3 “);
8 n2 l9 L! k' ?' [3 ?' O9 A22. } $ d3 n! H6 U ~. q m W
23. }
4 S' D1 ~! h y: q+ ?What is the result?
6 w, H$ S D1 u# TA. 2 $ d9 V% p0 T+ d: k6 w6 H
B. 3
1 M1 d+ l& m; m( G) uC. 1 2
/ A" V, _: H7 ^) t& @D. 2 3 3 N$ s" L, R5 p* L* v* h d Z- T7 m
E. 1 2 3 , B$ b4 u! } b# V9 A
F. Compilation fails. # n; @ k$ n1 ?9 b2 O9 X
G. Au exceptional is thrown at runtime. Question 2 Assume that country is set for each class. Given: 10. public class Money {
7 `' A v9 Y. W( p J( V0 a' I11. private String country, name; ( F4 Y' l( P3 B; ^4 c `$ a/ x
12. public String getCountry() { return country; }
' o% z: Y3 y$ v! @$ _. @! K13.} and: 24. class Yen extends Money {
2 ]) }# B! L$ D1 t/ z25. public String getCountry() { return super.country; }
, ^7 b2 L V9 y- ~26. }
- D8 W0 }2 V( Y/ \27.
/ ~/ ^0 S$ y! u* [2 y+ e% l28. class Euro extends Money { 5 D! v& A4 c- q: F
29. public String getCountry(String timeZone) {
- i+ Q1 l- ?& I, u30. return super.getCountry();
- F. }1 Z5 U% a0 @6 z& Q: t7 d31. } $ I9 e% n V4 f7 u; g( n% X
32. } ( ?4 `7 G) ]/ y3 G9 z! D3 T
Which two are correct? (Choose two.) A. Yen returns correct values. 7 [" T: T" A8 |$ M0 R1 m# A
B. Euro returns correct values.
- I- s* L# y. ZC. An exception is thrown at runtime.
0 W2 i0 V) U5 Y7 gD. Yen and Euro both return correct values. ( V6 F- H7 i3 ~$ d7 l s
E. Compilation fails because of an error at line 25. 9 h0 f* n# b$ k! L$ _; T
F. Compilation fails because of an error at line 30. Question 3 Given: 1. class TestA {
& z4 l( `' g! b1 s5 d- s2. public void start() { System.out.println(”TestA”); }
' D! y1 D& Q W9 h2 l- ~+ P3. }
; T" f. P+ f$ C7 @4. public class TestB extends TestA { 2 M7 a$ U; ]2 m
5. public void start() { System.out.println(”TestB”); } 5 a |+ [ |) y* D! e
6. public static void main(String[] args) { , ~. r- i+ Z3 Z* k; p( P
7. ((TestA)new TestB()).start(); 2 D4 d, e; s J! n, \
8. }
0 N' D2 [3 M4 s" o N9. } n4 d- Y% |2 H" T8 O
What is the result? A. TestA
; W& H$ I( Q) `& s1 M, d. ]/ NB. TestB
! i! o* R" N# ~. TC. Compilation fails.
- p& t8 J4 _% V0 {D. An exception is thrown at runtime. Question 4 Given: 11. public static void main(String[] args) {
4 ]( Z4 L; I" q9 C6 A/ K12. String str = “null’; + g, I/ Q; ?( q d% ]# n9 ^/ I, O ?
13. if (str == null) {
/ ]8 [4 P0 Q2 |14. System.out.println(”null”);
! J+ U4 G1 \. t# T15. } else (str.length() == 0) {
8 h+ m' |' a6 B9 {16. System.out.println(”zero”);
/ V5 C% B, O4 u! r0 k U17. } else {
) }% X6 K: `& |( m. \' S' ]18. System.out.println(”some”); 5 ~$ I* X, Y" o: ]' t1 e' N
19. } ' B7 J! m5 D4 f+ w; V E: n* o. }+ ^
20. }
" x4 J' |/ p( K* e0 c2 k) Z‘What is the result? A. null
/ J8 e- B7 |" ^5 s, pB. zero 5 K" T0 ]7 K' g/ M( T5 H
C. some
; M' F! c+ y6 Y$ a& kD. Compilation fails.
! z3 j/ m! @5 n; \E. An exception is thrown at runtime. Question 5 Given: 33. try {
+ w) J, J, f& ]0 |$ ]7 d34. // some code here / R2 `7 P: v/ T3 S+ _% D: v
35. } catch (NullPointerException e1) { $ Y/ a3 h2 L) E3 ^$ J# R1 T/ Y
36. System.out.print(”a”); 1 x* b. x/ G( H# v
37. } catch (RuntimeException e2) { 5 p# h3 _ }# I! u9 j! ~
38. System.out.print(”b”);
* g) v. \# j) u( M, r39. } finally { - X$ b3 n/ Y! {9 A
40. System.out.print(”c”); 1 f$ a. q1 y7 t
41. }
& f# k" f* j$ Q9 ^, rWhat is the result if a NullPointerException occurs on line 34? 6 Y, a4 L) z; K, a9 v4 X
A. c
% T: b) ]* X% C1 H2 h* y5 N1 gB. a % E& J( R8 b$ f* W
C. ab
+ ]# n. S, |( Q( f" u# cD. ac : k( X/ X& P; r: A2 K; S( K
E. bc , o- m. W( p# B7 @, [) p0 {. [4 h; c
F. abc Question 6 Given this method in a class: 21. public String toString() {
0 c8 C2 i+ ~/ m* c+ j; k22. StringBuffer buffer = new StringBuffer();
E$ w! x7 |6 o& j- Q; S h23. buffer.append(’<’); R# a4 A) k# O
24. buffer.append(this.name); & `4 @: S/ G1 o: m1 t/ T5 W0 j0 E
25. buffer.append(’>’); 1 J& \/ f$ o4 M& ^; X
26. return buffer.toString(); - S7 L: M$ E. O7 H" b. p2 _
27. }
% b# y/ J; }" z) D0 m: xWhich is true? A. This code is NOT thread-safe.
/ V( R3 E% j7 c) [# l: O( x3 nB. The programmer can replace StringBuffer with StringBuilder with no
0 l0 A, U5 ?. _# z( G% cother changes.
; E$ \4 o( S* U, MC. This code will perform well and converting the code to use & {$ W" a3 O/ E
StringBuilder will not enhance the performance. 8 k* G& [& O1 \! K, o. K/ W
D. This code will perform poorly. For better performance, the code 1 k5 y" m/ s$ y4 ]& B
should be rewritten: return “<“+ this.name + “>”; Question 7 Given: 11. String test= “a1b2c3”;
+ p/ k7 B, j9 O5 @, B& E" S$ E12. String[] tokens = test.split(”\\d”);
) H; D8 G5 ~( G6 \6 i3 n3 e& q6 }. d13. for(String s: tokens) System.out.print(s +“ “); 3 x' i' N6 R _& `( X) z6 H
What is the result?
9 e# c& m/ D. ?3 x8 iA. a b c
5 A1 x8 P9 v1 P8 h7 v3 z F: Z7 hB. 1 2 3
! n9 u7 Q( K4 W, zC. a1b2c3 , v/ K6 r3 V/ e, x0 Y' g8 x
D. a1 b2 c3
7 a0 m, A) O. u- N+ kE. Compilation fails. ! A0 K+ P" Z8 _5 q/ f
F. The code runs with no output.
& r1 [. V- _( f7 tG. 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 8 ?: B/ p; v$ R$ `# F+ [) k
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