2022java期末考试试题及答案.docx

2022java期末考试试题及答案2022年java期末考试试题及答案1.请看下列代码：classClassA{}classClassBextendsClassA{}classClassCextendsClassA{}publicclassTest{publicstaticvoidmain(String[]args){ClassAp0=newClassA();ClassBp1=newClassB();ClassCp2=newClassC();ClassAp3=newClassB();ClassAp4=newClassC();<插入代码>}}可以在<插入代码>处，填入的代码正确的是()A.p0=p1;B.p1=p2;C.p2=p4;D.p2=(ClassC)p1;正确答案：A2.运行下面程序:publicclassFoo{publicstaticvoidmain(String[]args){StringBuffera=newStringBuffer("A");StringBufferb=newStringBuffer("B");operator(a,b);System.out.println(a+","+b);}publicstaticvoidoperator(StringBufferx,StringBuffery){x.append(y);y=x;}}输出的结果是：()。A.A,BB.A,AC.B,BD.AB,B正确答案：D3.下列代码的输出结果是:()。publicclassA{publicvoidinfo(){System.out.println("Ainfo");}}publicclassBextendsA{publicvoidinfo(){System.out.println("Binfo");}publicstaticvoidmain(String[]args){Bb=newB();Aa=b;a.info();}}A.BinfoAinfoB.AinfoBinfoC.AinfoD.Binfo正确答案：D4.下列代码运行的结果是()。publicclassBase{publicstaticfinalStringFOO="foo";publicstaticvoidmain(String[]args){Baseb=newBase();Subs=newSub();System.out.print(Base.FOO);System.out.print(Sub.FOO);System.out.print(b.FOO);System.out.print(s.FOO);System.out.print(((Base)s).FOO);}}classSubextendsBase{publicstaticfinalStringFOO="bar";}A.foofoofoofoofooB.foobarfoobarbarC.foobarfoofoofooD.foobarfoobarfoo正确答案：D5.执行下列语句：inta=0x9af700;//00000010011010111101110000000000a<<=2;变量a的值为：()。A.0x26bdc00B.0xc6bdc00C.0x3fa0000D.0x7e02ffff正确答案：A6.下面的代码用于对数组arr实现冒泡排序：for(inti=0;i<arr.length-1;i++){booleanisSwap=false;空白处if(!isSwap)break;}下列选项中，空白处可以填入的代码是：()。//每轮比较结束把最小的放在前面A.for(intj=arr.length-1;j>i;j--){if(arr[j]<arr[j-1]){inttemp=arr[j];arr[j]=arr[j-1];arr[j-1]=temp;isSwap=true;}}B.for(intj=arr.length-1;j>0;j--){if(arr[j]<arr[j-1]){inttemp=arr[j];arr[j]=arr[j-1];arr[j-1]=temp;isSwap=true;}}C.for(intj=i+1;j<arr.length;j++){if(arr[j]<arr[j-1]){inttemp=arr[j];arr