s1
s2
s2 和 s3
s2 和 s4
第1题:
下列哪个选项的java源文件程序段是不正确的? ( )
A.package testpackage; public class Test{ }
B.import java.io.*; package testpackage; public class Test{ }
C.import java.i.*; class Person{} public class Test{ }
D.import java.io.*; import java.awt.*; public class Test { }
第2题:
1. public interface A { 2. public void doSomething(String thing); 3. } 1. public class AImpl implements A { 2. public void doSomething(String msg) { } 3. } 1. public class B { 2. public A doit() { 3. // more code here 4. } 5. 6. public String execute() { 7. // more code here 8. } 9. } 1. public class C extends B { 2. public AImpl doit() { 3. // more code here 4. } 5. 6. public Object execute() { 7. // more code here 8. } 9. } Which statement is true about the classes and interfaces in the exhibit?()
第3题:
下列Java源程序结构中前三种语句的次序,正确的是
A.import, package, public class
B.import必为首,其他不限
C.public class, import, package
D.package, import, public class
第4题:
Given classes defined in two different files: 1. package util; 2. public class BitUtils { 3. private static void process(byte[] b) { } 4. } 1. package app; 2. public class SomeApp { 3. public static void main(String[] args) { 4. byte[] bytes = new byte[256]; 5. // insert code here 6. } 7. } What is required at line 5 in class SomeApp to use the process method of BitUtils?()
第5题:
1. public class A { 2. void A() { 3. System.out.println(“Class A”); 4. } 5. public static void main(String[] args) { 6. new A(); 7. } 8. } What is the result?()
第6题:
1. public class Target { 2. private int i = 0; 3. public int addOne() { 4. return ++i; 5. } 6. } And: 1. public class Client { 2. public static void main(String[] args) { 3. System.out.println(new Target().addOne()); 4. } 5. } Which change can you make to Target without affecting Client?()
第7题:
1. public class a { 2. public void method1() { 3. try { 4. B b=new b(); 5. b.method2(); 6. // more code here 7. } catch (TestException te) { 8. throw new RuntimeException(te); 9. } 10. } 11. } 1. public class b { 2. public void method2() throws TestException { 3. // more code here 4. } 5. } 1. public class TestException extends Exception { 2. } Given: 31. public void method() { 32. A a=new a(); 33. a.method1(); 34. } Which is true if a TestException is thrown on line 3 of class b?()
第8题:
下列哪个选项的java源文件代码片段是不正确的?
A.package testpackage; public class Test{ }
B.import java. io. *; package testpaekage; public class Test { }
C.import java.io.*; class Person { } public class Test { }
D.import java.io.*; import java. awt.*; public class Test{ }
第9题:
Given a file GrizzlyBear.java: 1. package animals.mammals; 2. 3. public class GrizzlyBear extends Bear { 4. void hunt() { 5. Salmon s = findSalmon(); 6. s.consume(); 7. } 8. } and another file, Salmon.java: 1. package animals.fish; 2. 3. public class Salmon extends Fish { 4. void consume() { /* do stuff */ } 5. } Assume both classes are defined in the correct directories for theft packages, and that the Mammal class correctly defines the findSalmon() method. Which two changes allow this code to compile correctly?()
第10题:
1. import java.util.*; 2. class ForInTest { 3. static List list = new ArrayList(); 4. 5. static List getList() { return list; } 6. 7. public static void main(String [] args) { 8. list.add("a"); list.add("b"); list.add("c"); 9. // insert code here 10. System.out.print(o); 11. } 12. } 第 9 行插入哪一项将输出 abc?()