SCJP题库 带达内考点分析⑤_⑧答案.doc

ANSWERModule 51.BCD 2. E 3.BDE 4.C 5.D 6.D 7.D 8.B 拖拽题1. Answer:String path = ;for(String dir : directories)path = path + File.separator + dir;File file = new File(path, filename);return file.exists();2. Answer: reader=new BufferedReader(new FileReader(in);writer=new BufferedWriter(new PrintWriter(new FileWriter(out);或 writer=new PrintWriter(new BufferedWriter(new FileWriter(out);3. Answer:tryString temp;while(temp=buffReader.readLine()!=null)System.out.println(temp);catch(IOException e)e.printStackTrace();4. Answer:import java.io.*;public class ReadFile public static void main(String args) tryFile x1 = new File(MyText.txt);feredReader x4 = new BufferedReader(x2);String x3 = null;while(x3 = x4.readLine() != null)System.out.println(x3);x4.close();catch(Exception ex)ex.printStackTrace();Module 61.D 2.BC 3.A 4.D 5.C 6.D 7.C 8.B 9.A 10.C 11.BE 12.D 13.A 14.E 15.CF 16.B 17.FG 18.D 19.B 20.C 21.D 22.B 23.D拖拽题1. Answer:Pi is approximately 3.141593 and E is approximately true2. Answer:while(scanner.hasNext()if(scanner.hasNextBoolean()System.out.println(scanner.nextBoolean() + ); else scanner.next();Module 71.A 2.B 3.A 4.C 5.D 6.D 7.D 8.F 9.B 10.B 11.B 12.B 13.AD 14.B 15.A 16.CE 17.A 18.B 19.AC 20.B 21.D 22.G 23.C 24.C 25.C 26.ACF 27.CDG 28.D 29.ABDE 30.ADE 31.DF 32.A拖拽题1. Answer:allows access to elements by their integer index-java.util.Listdefines the method V get(Object key)-java.util.Mapis designed for holding elements prior to processing-java.util.Queuecontains no pair of elements e1 and e2, such that e1.equals(e2)-java.util.Set2. Answer:public class NumberNamesprivate HashMapmap=new HashMap;public void put(String name,int value)map.put(name,value);public Set getNames()return map.keySet();3. Answer: m1(listA); Compiles and runs without errorm2(listA); Compiles and runs without errorm1(listB); Compiles and runs without errorm2(listB); Compilation failsm1(listO); Compilation failsm2(listO); Compilation fails4. Answer: import java.util.*;public class MyInt implements Comparablepublic static void main(String args) ArrayList list=new ArrayList();list.add(new MyInt(2);list.add(new MyInt(1);Collections.sort(list);System.out.println(list);private int i;public MyInt(int i)this.i=i;public String toString()return Integer.toString(i);public int compareTo(Object o) MyInt i2=(MyInt)o;return i-i2.i;5. Answer:public void takeList(ArrayList list) -Compilation succeedspublic void takeList(ArrayList list) -Compilation succeedspublic void takeList(ArrayList list) -Compilation failspublic void takeList(ArrayList list)-Compilation succeedspublic void takeList(ArrayList list)-Compilation succeedspublic void takeList(ArrayList list) -Compilation fails6. Answer:public class GenericBpublic T foo;public void setFoo(T foo)this.foo = foo;public T getFoo()return foo;7. Answer:ArrayList x1=new ArrayList();foo(x1); /Compilation of the first statement succeeds, but compilation failsdue to an error in the second statementArrayList x2=new ArrayList();foo(x2); /Compilation fails due to an error in the first statement.ArrayList x3=new ArrayList();foo(x3); /Compilation succeedsArrayList x4=new ArrayList();foo(x4); /Compilation succeeds8. Answer:public class Genprivate T object;public Gen(T object)this.object = object;public T getObject()return object;9. Answer:list.add(Foo); Compilation failslist = new ArrayList(); Compilation succeedslist = new ArrayList(); Compilation failsString s = list.get(0); Compilation succeedsObject o = list; Compilation succeeds10. Answer:import java.util.*;public class _166 public static void main(String args) List list=new LinkedList();list.add(one);list.add(two);System.out.println(list.get(0).length();Module 81.DF 2.B 3.E 4.AC 5.B 6.C 7.DE 8.D 9.C 10.E 11.F 12.A 13.E 14.G 15.ACE 16.EG 17.AD 18.CEF 19.E 20.ABE拖拽题1. Answer:startedraninterruptingendedno more output2. Answer:t.run();t.join();t.doIt();3. Answer:public class Flags2 private boolean isReady=false;public synchronized void produce()isReady=true;notifyAll();public synchronized void consume(