System.out.print(a[i]+"");
System.out.println();
}
}
7.下面程序的运行结果是(true,false)。
publicclassStringTest{
publicstaticvoidmain(Stringargs[]){
Strings1=newString("abcde");
Strings2=newString("abcde");
booleanb1=s1.equals(s2);
booleanb2=s1==s2;
System.out.print(b1+","+b2);
}
}
8.下面程序运行时,若输入10,则输出结果是()。
publicclasstest{
publicstaticvoidmain(Stringargs[])throwsIOException{
BufferedReaderbuf=newBufferedReader(
newInputStreamReader(System.in));
while(true){
Stringstr=buf.readLine();
if(str.equals("quit"))
break;
intx=Integer.parseInt(str);
System.out.println(x*x);
}
System.out.println(“OK”);
}
}
9.下面程序的运行结果是()。
publicclassT{
publicstaticvoidmain(Stringargs[]){
Setset=newHashSet();
set.add(newInteger(10));
set.add(newInteger(5));
set.add(newInteger(15));
set.add(newInteger(5));
set.add(newInteger(10));
System.out.println("size="+set.size());
Iteratorit=set.iterator();
while(it.hasNext()){
System.out.print(it.next()+"");
}
}
}
10.下面程序的运行结果是()。
publicclassA{
classDog{
privateStringname;
privateintage;
publicintstep;
Dog(Strings,inta){
name=s;
age=a;
step=0;
}
publicvoidrun(Dogfast){
fast.step++;
}
}
publicstaticvoidmain(Stringargs[]){
Aa=newA();
Dogdog=a.newDog("Tom",3);
dog.step=25;
dog.run(dog);
System.out.println(dog.step);
}
}
11.下面程序的运行结果是()。
classA{
intx=1,y=2;
doubleadd(){returnx+y;}
}
classBextendsA{
intx=10,y=20;
doubleadd(){returnsuper.x+super.y;}
}
classTakecare{
publicstaticvoidmain(String[]args){
Aa=newA();
Bb=newB();
System.out.println("a.add="+a.add());
System.out.println("b.add="+b.add());
}
}
12.下面程序的运行结果是()。
for(inti=0;i<5;i++){
switch(i){
default:
System.out.print("default\t");
case0:
System.out.print("zero\t");
i++;
break;
case1:
System.out.print("one\t");
case2:
System.out.print("two\t");
i++;
}
}
13.下面程序的运行结果是()。
publicclassExample{
Stringstr=newString("good");
char[]ch={'a','b','c'};
publicvoidchange(Stringstr,charch[]){
str="testok";
ch[0]='g';
}
publicstaticvoidmain(Stringargs[]){
Exampleexample=newExample();
example.change(example.str,example.ch);
System.out.print(example.str+"and");
System.out.print(example.ch);
}
}
14.下面程序的运行结果是()。
classA{
publicStringShow(Dobj){return("AandD");}
publicStringShow(Aobj){return("AandA");}
}
classBextendsA{
publicStringShow(Bobj){return("BandB");}
publicStringShow(Aobj){return("BandA");}
}
classCextendsB{
publicStringShow(Cobj){return("CandC");}
publicStringShow(Bobj){return("CandB");}
}
classDextendsB{
publicStringShow(Dobj){return("DandD");}
publicStringShow(Bobj){return("DandB");}
}
publicclassmain{
publicstaticvoidmain(Stringargs[]){
Aa1=newA();
Aa2=newB();
Bb=newB();
Cc=newC();
Dd=newD();
System.out.println(a1.Show(b));①
System.out.println(a1.Show(c));②
System.out.println(a1.Show(d));③
System.out.println(a2.Show(b));④
System.out.println(a2.Show(c));⑤
System.out.println(a2.Show(d));⑥
System.out.println(b.Show(b));⑦
System.out.println(b.Show(c));⑧
System.out.println(b.Show(d));⑨
}
}
15.下面程序的运行结果是()。
publicclassExampleextendsTT{
publicstaticvoidmain(Stringargs[]){
Examplet=newExample("Tom");
}
publicExample(Strings){
super(s);
System.out.println("Howdoyoudo?
");
}
publicExample(){
this("IamTom");
}
}
classTT{
publicTT(){
System.out.println("Whatapleasure!
");
}
publicTT(Strings){
this();
System.out.println("Iam"+s);
}
}
16.下面程序的运行结果是()。
publicclassExample{
publicstaticvoidmain(Stringargs[]){
for(inti=0;i<2;i++){
resume:
for(intj=0;j<3;j++){
for(intk=0;k<2;k++){
System.out.println(i+""+j+""+k);
if(i==1&&k==0)breakresume;
}
}
}
}
}
17.下面程序的运行结果是()。
publicclassATest{
publicstaticvoidmain(Stringargs[]){
SuperClasssb=newSubClass();
System.out.println(sb.fun());
}
}
classSuperClass{
inta=22,b=5;
intfun(){
returna/b;
}
}
classSubClassextendsSuperClass{
intfun(){
returna%b;
}
}
18.下面程序的运行结果是()。
publicclassE
{
publicstaticvoidmain(Stringargs[]){
charx='你',y='e',z='吃';
if(x>'A'){
y='爱';
z='情';
}elsey='我';
z='她';
System.out.println(""+x+y+z);
}
}
19.下面程序的运行结果是()。
classTT{
publicTT(){
System.out.println("Whatapeasure!
");
}
publicTT(Strings){
this();
System.out.println("Iam"+s);
}
}
publicclassExampleextendsTT{
publicstaticvoidmain(Stringargs[]){
Exampleexample=newExample();
}
publicExample(Strings){
super(s);
System.out.println("Howdoyouodo?
");
}
publicExample(){
this("IamTom");
}
}
20.下面程序的运行结果是()。
publicclassExample{
publicstaticvoidmain(Stringargs[]){
intcount=0;
for(inti=0;i<3;i++){
resume:
for(intj=0;j<4;j++){
for(intk=0;k<5;k++){
++count;
if(i==1&&j==2&&k==3)breakresume;
}
System.out.println("\tcount="+count);
}
}
}
}
21.下面程序的运行结果是()。
publicclassA{
classDog{
privateStringname;
privateintage;
publicintstep;
Dog(Strings,inta){
name=s;
age=a;
step=0;
}
publicvoidrun(Dogfast){
fast.step--;
}
}
publicstaticvoidmain(Stringargs[]){
Aa=newA();
Dogdog=a.newDog("Tom",3);
dog.step=30;
dog.run(dog);
System.out.println(dog.step);
}
}
22.下面程序的运行结果是()。
importjava.io.*;
publicclassTestFile{
publicstaticvoidmain(Stringargs[])throwsException{
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));
BufferedWriterbw=newBufferedWriter(newFileWriter("input.txt"));
Strings;
while(true){
System.out.print("请输入一个字符串:
");
System.out.flush();
s=br.readLine();
if(s.length()==0)
break;
bw.write(s);
bw.newLine();
}
bw.close();
}
}
23.下面程序的运行结果是()。
classA{
publicStringShow(Dobj){return("AandD");}
publicStringShow(Aobj){return("AandA");}
}
classBextendsA{
publicStringShow(Bobj){return("BandB");}
publicStringShow(Aobj){return("BandA");}
}
classCextendsB{
publicStringShow(Cobj){return("CandC");}
publicStringShow(Bobj){return("CandB");}
}
classDextendsB{
publicStringShow(Dobj){return("DandD");}
publicStringShow(Bobj){return("DandB");}
}
publicclassmain{
publicstaticvoidmain(Stringargs[]){
Aa1=newA();
Aa2=newB();
Bb=newB();
Cc=newC();
Dd=newD();
System.out.println(a1.Show(b));①
System.out.println(a1.Show(c));②
System.out.println(a1.Show(d));③
System.out.println(a2.Show(b));④
System.out.println(a2.Show(c));⑤
System.out.println(a2.Show(d));⑥
System.out