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选择题 1:关于垃圾收集的哪些叙述是对的。 A.程序开发者必须自己创建一个线程进行内存释放的工作。 B.垃圾收集将检查并释放不再使用的内存。 C.垃圾收集允许程序开发者明确指定并立即释放该内存。 D.垃圾收集能够在期望的时间释放被java对象使用的内存。 2: 1. Strings=”ExampleString”;Whichoperationisnotlegal?String s=”Example String”;Which operation is not legal?A.int i=s.length(); B.s3=”x”; C.String short_s=s.trim(); D.String t=”root”+s; 3:What is written to the standard output given the following statement:System.out.println(4|7); Select the right answer: A.4 B.5 C.6 D.7 4:Which declares for native method in a java class corrected? A.public native void method() B.public native void method(); C.public native method(); D.public void native method(); 5: 1. Whathappenswhenyoutrytocompileandrunthefollowingprogram? 2. classMystery 3. Strings; 4. publicstaticvoidmain(Stringargs) 5. Mysterym=newMystery(); 6. m.go(); 7. 8. voidMystery() 9. s=”constructor”; 10. 11. voidgo() 12. System.out.println(s); 13. 14. What happens when you try to compile and run the following program?class MysteryString s;public static void main(String args)Mystery m=new Mystery();m.go();void Mystery()s=”constructor”;void go()System.out.println(s);A.this code compliles but throws an exception at runtime B.this code runs but nothing appears in the standard output C.this code runs and “constructor” in the standard output D.this code runs and writes ”null” in the standard output 6:public class Parent int change() class Child extends Parent Which methods can be added into class Child? A.public int change() B.abstract int chang() C.private int change() D.none 7: 1. Whatwillhappenwhenyouattempttocompileandrunthefollowingcode? 2. 3. publicclassStatic 4. 5. 6. 7. static8. 9. 10. 11. intx=5; 12. 13. 14. 15. staticintx,y; 16. 17. publicstaticvoidmain(Stringargs) 18. 19. 20. 21. x-; 22. 23. myMethod(); 24. 25. System.out.println(x+y+x); 26. 27. 28. 29. publicstaticvoidmyMethod() 30. 31. 32. 33. y=x+x; 34. 35. 36. 37. 38. 39. Choices:What will happen when you attempt to compile and run the following code? public class Staticstaticint x = 5; static int x,y;public static void main(String args) x-; myMethod(); System.out.println(x + y + +x); public static void myMethod()y = x+ + +x; Choices:A.prints : 2 B.prints : 3 C.prints : 7 D.prints : 8 8:A class design requires that a particular member variable must be accessible for direct access by any subclasses of this class. but otherwise not by classes which are not members of the same package. What should be done to achieve this? A.The variable should be marked public B.The variable should be marked private C.The variable should be marked protected D.The variable should have no special access modifier 9: 1. Givethefollowingcode: 2. publicclassExample 3. publicstaticvoidmain(Stringargs) 4. intl=0; 5. do 6. System.out.println(“Doingitforlis:”+l); 7. while(-l0) 8. System.out.println(“Finish”); 9. 10. 11. Whichwellbeoutput:Give the following code:public class Examplepublic static void main(String args )int l=0;doSystem.out.println(“Doing it for l is:”+l);while(-l0)System.out.println(“Finish”);Which well be output: A.Doing it for l is 3 B.Doing it for l is 1 C.Doing it for l is 2 D.Doing it for l is 0 10:假定a和b为int型变量,则执行下述语句组后,b的值为 a=1; b=10; do b-=a; a+; while (b-=0:methodB(); 10. 11. System.out.println(i); 12. 13. 14. 15. publicvoidmethodB() 16. 17. System.out.println(Thevaluemustnotbenegative); 18. 19. 20. 21. publicstaticvoidmain(Stringargs) 22. 23. AssertTesttest=newAssertTest(); 24. 25. test.methodA(-10); 26. 27. 28. 29. What will happen when you attempt to compile and run the following code?(Assume that the code is compiled and run with assertions enabled.)public class AssertTestpublic void methodA(int i)assert i = 0 : methodB();System.out.println(i);public void methodB() System.out.println(The value must not be negative);public static void main(String args)AssertTest test = new AssertTest();test.methodA(-10); A.it will print -10 B.it will result in AssertionError showing the message-“the value must not be negative”. C.the code will not compile. D.None of these. 18:Which is the main() method return of a application? A.String B.byte C.char D.void 19:设有变量说明语句int a=1,b=0; 则执行以下程序段的输出结果为（ ）。 switch (a) case 1: switch (b) case 0:printf(*0*);break; case 1:printf(*1*);break; case 2:printf(*2*);break; printf(n); A.*0* B.*0*2* C.*0*1*2* D.有语法错误 20: 1. Whatistheresultwhenyoucompileandrunthefollowingcode? 2. 3. publicclassTest 4. 5. 6. 7. publicvoidmethod() 8. 9. 10. 11. for(inti=0;i3;i+) 12. 13. 14. 15. System.out.print(i); 16. 17. 18. 19. System.out.print(i); 20. 21. 22. 23. 24. 25. Choices:What is the result when you compile and run the following code? public class Test public void method()for(int i = 0; i 3; i+) System.out.print(i); System.out.print(i); Choices:A.0122 B.0123 C.Compilation error D.None of these 简答题 21:已知abc+cba=1333，其中a,b,c均为一位数，编程求出满足条件的a,b,c所有组合。 22:How to use final to class,method and data? 23:介绍在Jsp中如何使用JavaBeans。 24:说明Jsp中errorPage的作用，应用范围。 25:请问你在什么情况下会在你的JAVA代码中使用可序列化？为什么放到HttpSession中的对象必须要是可序列化的？ 26:试举例说明一个典型的垃圾回收算法？ 27:Java中的异常处理机制的简单原理和应用。 28:EJB是基于哪些技术实现的?并说出SessionBean和EntityBean的区别，StatefulBean和StatelessBean的区别。 29:将一个链表逆序. 30:编写一个C语言函数(JAVA方法)，要求输入一个url，输出该url是首页、目录页或者其他url 如下形式叫做首页： / / / / / 如下形式叫做目录页： /greenhouses-gas-global-green-house-warming/ .tw/