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 { 7 [9 ^. {7 r' g3 L6 i
12. public static void main(String [] args) {
) s! @ W2 K# T8 h! }13. int x =5;
- X& i4 y- Y/ Q14. boolean b1 = true;
: }/ g! s/ J: M, O& o2 e6 c15. boolean b2 = false;
2 F6 P% w" u" g: F: K17.if((x==4) && !b2)
3 ^; J8 A# `# t- B1 u: V18. System.out.print(”l “); , l! {% |) [- `0 ]
19. System.out.print(”2 “); 6 f# I8 L. T, D q" ?
20. if ((b2 = true) && b1) . |# @% m) c* z( |! s( {" M+ |. u
21. System.out.print(”3 “); O6 ^+ ~5 `5 v( p" t+ T3 ~
22. } & |' E- I* I2 L! F
23. }
4 S; K4 j" q/ T( Z6 F& cWhat is the result?
3 m5 L A0 m' O3 P4 X6 M! LA. 2
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D. 2 3 ' {9 ]$ b4 S6 L. m' T
E. 1 2 3 v: p0 Y) e4 _* ?4 S U, d. c
F. Compilation fails. 3 ?! D C" q4 a2 }6 @/ ^; v0 f
G. Au exceptional is thrown at runtime. Question 2 Assume that country is set for each class. Given: 10. public class Money {
% v3 v0 `6 {* {3 A' j+ ~11. private String country, name;
) |/ _' U* f1 Q2 ^3 |4 v4 E: U$ y: x12. public String getCountry() { return country; } . }1 M7 D* Z9 ?* G
13.} and: 24. class Yen extends Money {
- [7 S! f( x/ A/ W) L7 F' z25. public String getCountry() { return super.country; } 5 F2 w% {6 I. N
26. }
3 {3 o# v, b9 P0 u% Q1 E27. T1 W( L% A1 p6 d, Z/ k
28. class Euro extends Money { 4 o3 j( }! }% y4 q8 s: Q& y
29. public String getCountry(String timeZone) {
; p; ]4 G; t3 S2 O30. return super.getCountry(); H4 V* b1 o; x* @7 Y& `
31. } ( Z6 A) ~- |7 w- M
32. } ! D3 p$ C5 Q" S9 n
Which two are correct? (Choose two.) A. Yen returns correct values. 8 \* d( w' D4 c; Z+ O+ P, U
B. Euro returns correct values. " F# a, s2 f8 z' ^' T- W6 J
C. An exception is thrown at runtime. : g9 r- q5 h" \2 B8 R; |: H
D. Yen and Euro both return correct values. ( r4 d% h5 H0 m! K# x& h5 f0 w
E. Compilation fails because of an error at line 25.
% J! V3 J3 O' I) w u# |& U2 P: @F. Compilation fails because of an error at line 30. Question 3 Given: 1. class TestA { - ~8 k# N2 G, z! V! J- R
2. public void start() { System.out.println(”TestA”); }
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4. public class TestB extends TestA {
0 n8 d. ?( H& n- Z/ A5. public void start() { System.out.println(”TestB”); }
0 c4 `% u3 E9 L9 k6. public static void main(String[] args) {
6 L! |. `! t! q5 x; b( N$ C) [$ [1 l. e7. ((TestA)new TestB()).start(); 2 |* l) ]2 n: D" p# ~5 U
8. } 3 ^5 |$ ?, D' E6 ?7 R; D! ?
9. } - P s7 J+ s4 U O7 M( M
What is the result? A. TestA - b* ~- a0 o& R
B. TestB / X. f% ~/ X- W0 }) y
C. Compilation fails. 4 n6 P9 ?7 h1 u2 q! ?$ y; @3 |
D. An exception is thrown at runtime. Question 4 Given: 11. public static void main(String[] args) { - L7 ]/ {3 V! l, Z9 @& c% Y
12. String str = “null’;
7 @& O# ~0 j9 R1 h! x- [13. if (str == null) {
" Q' G) r- H! [14. System.out.println(”null”);
7 \5 ~' Z9 X" z# h Y+ C: C( k& [9 C15. } else (str.length() == 0) { 2 Z5 `4 J, t n
16. System.out.println(”zero”); , R* [0 R& O. `; ]( s& H
17. } else { & g5 C: c* _+ l0 i; T3 w) F
18. System.out.println(”some”); - [9 D+ N0 z& R& W' Q( k/ o
19. }
+ T4 d5 j& I$ l7 E5 A: r& w: v20. }
8 O/ Y1 I' z8 x8 B* |" R‘What is the result? A. null
! g2 R; c. z1 G" E$ v0 x4 yB. zero
5 t( ^ s. y1 e* DC. some / I! k7 Y9 }: y/ m w! R
D. Compilation fails. : Y! W+ i3 X1 ?% A7 `1 k
E. An exception is thrown at runtime. Question 5 Given: 33. try { : r& k `: k& m( j
34. // some code here 2 j7 }9 p5 C& v/ @$ [0 ~
35. } catch (NullPointerException e1) {
6 z8 |0 p. F4 {5 L* Z36. System.out.print(”a”); # ^: H7 i |/ D1 U& q
37. } catch (RuntimeException e2) {
0 ^2 J3 k2 [' U) E( y38. System.out.print(”b”); 0 g9 u: x/ Y+ t( Y
39. } finally {
) h3 V. I% G0 t40. System.out.print(”c”); 9 Z$ i7 w, z; _4 y7 F# E3 H, u
41. }
r% Q" [2 O) E8 o2 O# gWhat is the result if a NullPointerException occurs on line 34?
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B. a
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F. abc Question 6 Given this method in a class: 21. public String toString() {
+ Q$ n; m8 V( Y( C22. StringBuffer buffer = new StringBuffer(); P+ ]; ]8 Y7 x. X; e
23. buffer.append(’<’); & F5 Y% ^; f" \% E# x' O: Y* F
24. buffer.append(this.name);
! \; Q( s- m8 A) s0 B6 ]8 i25. buffer.append(’>’); 6 U# A' T9 T u2 C6 D1 |! d
26. return buffer.toString(); + G7 K0 S5 L% Q# e! j( S, u3 x
27. }
' a6 {7 U u" IWhich is true? A. This code is NOT thread-safe. 6 r* l$ W, t. \1 U; T/ M0 F+ ~9 k
B. The programmer can replace StringBuffer with StringBuilder with no ~, ]% K1 O% t* Q
other changes.
! i( H" t& g- h/ ?* u+ wC. This code will perform well and converting the code to use
0 h( o0 z! k1 ]& n8 AStringBuilder will not enhance the performance. 3 a u @8 h" h; C. a
D. This code will perform poorly. For better performance, the code
% ]8 R$ S; j- K1 H" wshould be rewritten: return “<“+ this.name + “>”; Question 7 Given: 11. String test= “a1b2c3”;
) G) \& ]# x0 P3 Q: c% c12. String[] tokens = test.split(”\\d”); " C) e8 c V. d# G6 t2 W
13. for(String s: tokens) System.out.print(s +“ “);
2 D9 N" ^3 Z% e* o s6 J# T- QWhat is the result? - r: G! R" w3 P# Z7 T( p- n9 l
A. a b c ; u0 o- d A# c2 n, C
B. 1 2 3
7 E- F8 j9 t5 i6 T [C. a1b2c3 . J* H. _" O1 A- @7 m5 H
D. a1 b2 c3 ; D% A( F/ a$ F% ~
E. Compilation fails.
/ G) Y/ N& z. Q1 b. t. F1 v9 {F. The code runs with no output. # F$ [% ~( S5 F
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
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