java考试

java考试,第1张

java考试

7-2 判断闰年

import java.util.*;

public class Main

{

    public static void main(String args[])

    {

        Scanner input=new Scanner(System.in);

        int y=input.nextInt();

        if(y%400==0)System.out.println("yes");

        else if(y%100==0)System.out.println("no");

        else if(y%4==0)System.out.println("yes");

        else System.out.println("no");     

    }

}

7-5 分解质因数

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        int a=sc.nextInt();

        int b=sc.nextInt();

        for (int i = a; i <= b; i++) {

            if (isPrime(i))continue;

            else prime(i);

        }

    }

    public static boolean isPrime(int n) {

        boolean ret=true;

        for (int i = 2; i <= Math.sqrt(n); i++) {

            if (n%i==0){

                ret=false;

                break;

            }

        }

        if (ret) System.out.println(n+"="+n);

        return ret;

    }

    public static void prime(int n){

        System.out.print(n+"=");

        for (int i = 2; i <= n; i++) {

            while (n%i==0&&n!=i){

                System.out.print(i+"*");

                n/=i;

            }

            if (i==n){

                System.out.println(i);

            }

        }

    }

}

7-6 统计最大数出现次数

import java.util.Scanner;

public class Main{

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        int a;

        int max=-1;

        int count=1;

        do {

            a=sc.nextInt();

            if (max

                max = a;

                count=1;

            }

            else if (max==a)count++;

        }while (a!=0);

            System.out.println("The largest number is "+max);

            System.out.println("The occurrence count of the largest number is "+count);

    }

}

7-10 jmu-Java-03面向对象基础-04-形状-继承 

import java.util.Scanner;

 

abstract class Shape {

double PI = 3.14;

 

public abstract double getPerimeter();

 

public abstract double getArea();

}

 

class Rectangle extends Shape {

int wide, len;

 

Rectangle(int a, int b) {

wide = a;

len = b;

}

 

@Override

public double getPerimeter() {

// TODO Auto-generated method stub

return 2 * (wide + len);

}

 

@Override

public double getArea() {

// TODO Auto-generated method stub

return wide * len;

}

public String toString(){

return "[width=" + wide + ", length=" + len + "]";

}

}

 

class Circle extends Shape {

int radius;

 

Circle(int _radius) {

radius = _radius;

}

 

@Override

public double getPerimeter() {

// TODO Auto-generated method stub

return radius * 2 * PI;

}

 

@Override

public double getArea() {

// TODO Auto-generated method stub

return radius * radius * PI;

}

 

public String toString(){

return "[radius=" + radius + "]";

}

 

}

 

public class Main {

public static void main(String[] args) {

Scanner in = new Scanner(System.in);

int n = in.nextInt();

in.nextLine();

Shape A[] = new Shape[n];

int k = 0, j = 0;

double sumAllArea = 0, sumAllPerimeter = 0;

for (int i = 0; i < n; i++) {

String S = in.next();

if (S.equals("rect")) {

int wide = in.nextInt(), len = in.nextInt();

in.nextLine();

A[i] = new Rectangle(wide, len);

} else if (S.equals("cir")) {

int radius = in.nextInt();

in.nextLine();

A[i] = new Circle(radius);

}

sumAllArea += A[i].getArea();

sumAllPerimeter += A[i].getPerimeter();

}

 

System.out.println(sumAllPerimeter);

System.out.println(sumAllArea);

System.out.print("[");

for (int i = 0; i < n; i++) {

if(i != 0)

System.out.print(", ");

if (A[i] instanceof Rectangle) {

System.out.print("Rectangle ");

System.out.print(A[i].toString());

}

else {

System.out.print("Circle ");

System.out.print(A[i].toString());

}

}

 

System.out.println("]");

 

for(int i = 0;i < n;i++) {

if(A[i] instanceof Rectangle) {

System.out.println("class Rectangle,class Shape");

}else {

System.out.println("class Circle,class Shape");

 

}

}

in.close();

}

}

7-11 jmu-Java-03面向对象-06-继承覆盖综合练习-Person、Student、Employee、Company (15 分)

import java.text.DecimalFormat;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Comparator;

import java.util.List;

import java.util.Scanner;

public class Main {

    public static void main(String[] args) throws InterruptedException {

       Scanner sc=new Scanner(System.in);

       List personList=new ArrayList();

       String name;

       int age;

       boolean gender;

       String stuNo;

       String clazz;

       String companyName;

       Company company;

       double salary;

       while(true) {

        String t=sc.next();

        if(t.equals("s")) {

        name=sc.next();

        age=sc.nextInt();

        gender=sc.nextBoolean();

        stuNo=sc.next();

        clazz=sc.next();

        if(name==null||stuNo==null||clazz==null) {

        continue;

        }

        personList.add(new Student(name, age, gender, stuNo, clazz));

        

       }else if(t.equals("e")){

        name=sc.next();

        age=sc.nextInt();

        gender=sc.nextBoolean();

        salary=sc.nextDouble();

        companyName=sc.next();

        company=new Company(companyName);

        if(name==null) {

        continue;

        }

       

        if(companyName==null) {

        companyName="null";

        }

        personList.add(new Employee(name, age, gender, company, salary));

       }else{         

        break;

       }

      

       }

      

       Collections.sort(personList, new Name_AgeComparator());

      

       for(int i=0;i

        

        System.out.println(personList.get(i).toString());

       

       }

     

       String str=sc.next();

       while(true) {

        if(str.equals("return")||str.equals("exit")) {

        break;

        }else {

          

               List stuList=new ArrayList();

               List empList=new ArrayList();

           

               boolean flag1=true;

               boolean flag2=true;

               for(int i=0;i

                if(personList.get(i).toString().indexOf("Student")>=0) {

                if(stuList.size()==0) {

                stuList.add(personList.get(i));

                }

                for(int j=0;j

                if(personList.get(i).equals(stuList.get(j))){

                flag1=false;

                }

                }

                if(flag1) {

                stuList.add(personList.get(i));

                

                }

                flag1=true;

                }else {

                if(empList.size()==0) {

                empList.add(personList.get(i));

                }

                for(int j=0;j

                if(personList.get(i).equals(empList.get(j))){

                flag2=false;

                }

                }

                if(flag2) {

                empList.add(personList.get(i));

                }

                flag2=true;

                }

               }

               System.out.println("stuList");

               for(int i=0;i

                

            System.out.println(stuList.get(i).toString());

           

               }

               System.out.println("empList");

               for(int i=0;i

                

            System.out.println(empList.get(i).toString());

           

               }

               break;

           }

        }

       

       

    }

    static class Name_AgeComparator implements Comparator{  

@Override

public int compare(Person o1, Person o2) {

 if(o1.name.compareTo(o2.name)==0) {

if(o1.age==o2.age) {

return 0;

}else if(o1.age

return -1;

}else {

return 1;

}

}else {

return(o1.name.compareTo(o2.name));

}

}

    

    }

    

    

}

abstract class Person{

String name;

int age;

boolean gender;

public Person(String name, int age, boolean gender) {

super();

this.name = name;

this.age = age;

this.gender = gender;

}

@Override

public String toString() {

return this.name+'-'+String.valueOf(this.age)+'-'+String.valueOf(this.gender);

}

@Override

public boolean equals(Object obj) {

if (this == obj)

return true;

if (obj == null)

return false;

if (getClass() != obj.getClass())

return false;

Person other = (Person) obj;

if (age != other.age)

return false;

if (gender != other.gender)

return false;

if (name == null) {

if (other.name != null)

return false;

} else if (!name.equals(other.name))

return false;

return true;

}

}

class Student extends Person{

String stuNo;

String clazz;

public Student(String name, int age, boolean gender, String stuNo, String clazz) {

super(name,age,gender);

this.clazz=clazz;

this.stuNo=stuNo;

}

@Override

public String toString() {

return"Student:"+ super.toString()+'-'+this.stuNo+'-'+this.clazz;

}

@Override

public boolean equals(Object obj) {

if (!super.equals(obj))

return false;

if (this == obj)

return true;

if (getClass() != obj.getClass())

return false;

Student other = (Student) obj;

if (clazz == null) {

if (other.clazz != null)

return false;

} else if (!clazz.equals(other.clazz))

return false;

if (stuNo == null) {

if (other.stuNo != null)

return false;

} else if (!stuNo.equals(other.stuNo))

return false;

return true;

}

}

class Company{

String name;

public Company(){

}

public Company(String name) {

this.name = name;

}

@Override

public String toString() {

return name;

}

@Override

public boolean equals(Object obj) {

if (this == obj)

return true;

if (obj == null)

return false;

if (getClass() != obj.getClass())

return false;

Company other = (Company) obj;

if (name == null) {

if (other.name != null)

return false;

} else if (!name.equals(other.name))

return false;

return true;

}

}

class Employee extends Person{

Company company;

double salary;

public Employee(String name, int age, boolean gender, Company company, double salary) {

super(name, age, gender);

this.company = company;

this.salary = salary;

}

@Override

public String toString() {

return "Employee:"+ super.toString()+'-'+company+'-'+salary;

}

@Override

public boolean equals(Object obj) {

if (!super.equals(obj))

return false;

if (this == obj)

return true;

if (getClass() != obj.getClass())

return false;

Employee other = (Employee) obj;

if (company == null) {

if (other.company != null)

return false;

}

else if (!company.equals(other.company))

return false;

DecimalFormat df = new DecimalFormat("#.#");

if (!df.format(salary) .equals( df.format(other.salary)))

return false;

return true;

}

}

7-15 USB接口的定义

interface USB{

void work();

void stop();

}

class Mouse implements USB{

@Override

public void work() {

System.out.println("我点点点");

}

@Override

public void stop() {

System.out.println("我不能点了");

}

}

class Upan implements USB{

@Override

public void work() {

System.out.println("我存存存");

}

@Override

public void stop() {

System.out.println("我走了");

}

}

public class Main {

public static void main(String[] args) {

// TODO Auto-generated method stub

USB usb1=new Mouse();

usb1.work();

usb1.stop();

USB usbs[]=new USB[2];

usbs[0]=new Upan();

usbs[1]=new Mouse();

for(int i=0;i

usbs[i].work();

usbs[i].stop();

}

}

}

7-16 jmu-Java-03面向对象基础-01-构造函数与toString

import java.util.Scanner;

class Person{     

    private String name = null;

    private int age = 0;

    private boolean gender = false;

    private int id = 0;

    

    public Person() {

        System.out.println("This is constructor");

        System.out.println(name+","+age+","+gender+","+id);

        System.out.println("Person [name="+name+", age="+age+", gender="+gender+", id="+id+"]");

    }

    

    public Person(String n, int a, boolean g) {    

        this.name = n;

        this.age = a;

        this.gender = g;

    }

    

    public String toString() {     

        System.out.println("Person [name="+this.name+", age="+this.age+", gender="+this.gender+", id="+0+"]");

        return name;

    }

}

public class Main {

    public static void main(String[] args) {

        // TODO Auto-generated method stub

        @SuppressWarnings("resource")

        Scanner reader = new Scanner(System.in);

        int number = reader.nextInt();

        Person[] per = new Person[number];    

        for(int i=0; i

            String name = reader.next();

            int age = reader.nextInt();

            boolean genter = reader.nextBoolean();

            per[i] = new Person(name,age,genter);

        }

        for(int x=per.length-1; x>=0;x--){    

            per[x].toString();

        }

        

        per.toString();

        @SuppressWarnings("unused")

        Person s = new Person();

    }

}

7-17 定义商品类,封装成员变量,输出对象

import java.util.Scanner;

class stuff{

    private String number;

    private String name;

    private double price;

    public String getNumber() {

        return number;

    }

    public void setNumber(String number) {

        this.number = number;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public double getPrice() {

        return price;

    }

    public void setPrice(double price) {

        this.price = price;

    }

    stuff(String number, String name,double price ) {

        this.name = name;

        this.number = number;

        this.price = price;

    }

    public String toString(){

        return getNumber()+","+getName()+","+getPrice();

    }

}

public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        String number = sc.next();

        String name = sc.next();

        double price = sc.nextDouble();

        stuff a = new stuff(number, name, price);

        System.out.println(a.toString());

    }

}

7-18 定义类与创建对象 

public class Main  {

    public static void main(String[] args) {

        Person p1=new Person("lili", 19);

        Person p2=new Person("lucy", 20);

        System.out.println("this person is "+p1.name+",her age is "+p1.age);

        System.out.println("this person is "+p2.name+",her age is "+p2.age);

    }

}

class Person {

    String name;

    int age;

    public Person(String name, int age) {

        this.name = name;

        this.age = age;

    }

}

7-14 教师类 

import java.util.Scanner;

class Teacher{

    int no;

    String name;

    String seminary;

    int age;

    public Teacher(){

}

    public Teacher(int no, String name,int age, String seminary) {

        this.no = no;

        this.name = name;

        this.seminary = seminary;

        this.age = age;

    }

    public int getNo() {

        return no;

}

    public void setNo(int no) {

        this.no = no;

}

    public String getName() {

        return name;

}

    public void setName(String name) {

        this.name = name;

}

    public String getSeminary() {

        return seminary;

}

    public void setSeminary(String seminary) {

        this.seminary = seminary;

}

    public int getAge() {

        return age;

}

    public void setAge(int age) {

        this.age = age;

}

    public boolean equals(Object obj){

        Teacher t=(Teacher) obj;

        if(this.no==t.no)

            return true;

        return false;

}

    public String toString(){

        return "no: "+this.no+", name:"+this.name+", age: "+this.age+", seminary: "+seminary;

}

}

public class Main {

    public static void main(String[] args) {

        Scanner s=new Scanner(System.in);

        Teacher t=new Teacher(s.nextInt(),s.next(),s.nextInt(),s.next());

        Teacher t1=new Teacher(s.nextInt(),s.next(),s.nextInt(),s.next());

        System.out.println(t.toString());

        System.out.println(t1.toString());

        System.out.println(t.equals(t1));

}

}

6-1 jmu-Java-06异常-finally 

System.out.println("resource open success");

}catch(Exception e){

    System.out.println(e);

}

try{

    resource.close();

    System.out.println("resource release success");

}catch(RuntimeException e){

    System.out.println(e);

}

6-2 jmu-Java-06异常-多种类型异常的捕获

catch(NumberFormatException e){

    System.out.println("number format exception");

    System.out.println(e);

}catch(IllegalArgumentException e){

    System.out.println("illegal argument exception");

    System.out.println(e);

}catch(Exception e){

    System.out.println("other exception");

    System.out.println(e);

}

6-3 接口与多态

class Circle implements Shap{

    Double r;

    final double PI=3.14;

    public Circle(double parseDouble) {

        super();

        this.r = parseDouble;

}

    @Override

    public double f() {

        if(r<=0) return 0;

        return 2*PI*r;

}

}

class Rect implements Shap{

    Double a,b;

    public Rect(double parseDouble, double parseDouble2) {

        super();

        this.a = parseDouble;

        this.b = parseDouble2;

}

    @Override

    public double f() {

        if(a<=0||b<=0) return 0;

        return 2*(a+b);

}

}

class Tri implements Shap{

    Double a,b,c;

    public Tri(double parseDouble, double parseDouble2, double parseDouble3) {

        super();

        this.a = parseDouble;

        this.b = parseDouble2;

        this.c = parseDouble3;

}

    @Override

    public double f() {

        if(a+b

        return a+b+c;

}

}

5-1

要求:根据Main类中main方法中的代码,设计满足要求的Student(学生)类:1)包含属性:int no(学号)、String name(姓名);2)满足Main类中main方法代码的说明要求。 Main类中main方法代码的说明:1)首先,从键盘接收形如“3 cuizhenyu 2 tiangang 1 dingchangqing 4 zhangfeng”的字符串,该字符串中包含了4个学生的学号和姓名(各学生以及学生的学号和姓名之间都用一个空格分隔,姓名中只包含英文字母),然后将该字符串内容中的前3个学生的学号及其姓名放到到Student数组stus中;2)将stus中的3个Student放入到HashSet stuSet中(注意:如果学生的学号相同,则认为是相同对象,不放入stuSet中);3)将第4个学生对象放入到stuSet中,如果第4个学生对象的学号与stuSet中已有学生对象的学号相同则不能放入。然后,打印出当前stuSet中学生对象的个数;4)用Arrays.sort方法对数组stus按照学生姓名的字母顺序排序(先比较首字母,首字母相同的比较第二个字母,以此类推),输出排序后的stus中3个学生对象的内容,每个学生对象的输出格式为“no=XX&name=YY”。

class Student implements Comparable {

private int no;

private String name;

public Student(int no, String name) {

this.no = no;

this.name = name;

}

public int getNo() {

return no;

}

public void setNo(int no) {

this.no = no;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

 

public String toString() {

return "no=" + no + "&name=" + name;

}

 

public int compareTo(Student o) {

if(this.name.compareTo(o.name)<0) {

return -1;

}

else if(this.name.compareTo(o.name)>0)return 1;

return 0;

}

@Override

public int hashCode() {

final int prime = 31;

int result = 1;

result = prime * result + no;

return result;

}

@Override

public boolean equals(Object obj) {

if (this == obj)

return true;

if (obj == null)

return false;

if (getClass() != obj.getClass())

return false;

Student other = (Student) obj;

if (no != other.no)

return false;

return true;

}

}

5-2

 class base {

    int x, y, z, w;

    public base(int a, int b) {

        x = a;

        y = b;

    }

    public base(int a, int b, int c, int d) {

空一:this(a,b);

空二:new base

5-3

根据输出结果,完成填空。

super(x);

System.out.println();

5-4

定义一个Person类,该类包括age,name两个数据成员和eat(),work()两个成员方法,并实现对两个数据成员的Getter方法。然后通过测试程序,实现相应对象的 *** 作。程序输出结果如下

private String name

 return name

"会生活"

new Person

 p.eat()

5-5

有如下父类和子类的定义,请根据要求填写代码。

 super(a);  

this.a = a*10;

super.a

this.a

选择:

2-1

以下二维数组的定义正确的是( )

B.

int a[][]=new int[3][]

2-2

下面那种类型不属于Java的基本数据类型?

D.

String

下面的数据声明及赋值哪一个是正确的?

D.

int i = 10;

2-4下列标识符(名字)命名原则中,符合规范的是___。

常量完全大写

2-5在JAVA中,给定代码片段如下所示,则编译运行后,输出结果是()。

for (int i = 0; i < 10; i++) {

    if (i == 10 - i) {

        break;

    }

    if (i % 3 != 0) {

        continue;

    }

    System.out.print(i + " ");

}

B.

0 3

2-6

以下选项中没有语法错误的是(       ) 。

C.

int  j=0;

for(int  k=0; j + k !=10; j++,k++) {

        System.out.println(“ j  is “+ j + “k  is”+ k);

}

2-7

以下代码段将创建几个对象?

String s1="bc";

String s2="bc";

D.

1

2-8

关于垃圾收集的哪些叙述是对的。

B.

垃圾收集将检查并释放不再使用的内存。

2-9

你怎样强制对一个对象立即进行垃圾收集?

E.

垃圾收集是不能被强迫立即执行

2-10

设有定义:String s=”World”;,下列语句错误的是( )。

D.

String str=s.append();

2-11

以下代码输出( )。

  public static void main(String[] args) {

    String[] tokens = "Welcome to Java".split("o");

    for (int i = 0; i < tokens.length; i++) {

      System.out.print(tokens[i] + " ");

    }

  }

C.

Welc me t  Java

2-12

请选择下面程序正确的输出结果( )

public class Main{

        public static void main(String args[ ]){

            String a = new String("A");

            String b = new String("B");

            mb_operate(a,b);

            System.out.println(a + "." + b);

}

static void mb_operate(String x,String y){

    x.concat(y);

    y=x;

}

}

A.

A.B

2-13

Java中,要对一个类实现for( : )形式的遍历,则该类必须实现下列哪一个接口?

D.

Iterable

2-14

在Java中,( )类可用于创建链表数据结构的对象

A.

linkedList

2-15

现在有一个方法:public static int info(int x,double y),下面那个方法是对本方法的正确重载?

C.

public static int info(int x,int y);

2-16

在Java中,一个类可同时定义许多同名的方法,这些方法的形式参数个数、类型或顺序各不相同,传回的值也可以不相同。这种面向对象程序的特性称为( )。

C.

重载

2-17

假设类A有如下定义,且a是A类的一个实例,则必定错误的选项是(  )。

class  A {

      int  i;

      static  String  s;

       void  method1() {   }

       static  void  method2()  {   }

}

C.

A.method1();

2-18

下面关于缺省构造方法的描述中正确的是( )

A.

当类中没有定义任何构造方法时,Java编译器将为这个类创建缺省构造方法

2-19

下述哪条关于构造方法的说法,不符合Java语法的规定( )。

2-20

以下代码的输出结果为( )。

public class Pass{

     static int j = 20;

     public void amethod(int x){

         x = x*2;

         j = j*2;

    }

    public static void main(String args[]){

        int i = 10;

        Pass p = new Pass();

        p.amethod(i);

        System.out.println(i+" and "+j);

  }

}

C.

10 and 40

2-21一个*.java文件中可以包含多少个public类?

A.

最多1个

2-22

对于构造方法,下列叙述不正确的是( )。

B.

构造方法的返回类型只能是void型,即在方法名前加void

2-23

以下程序运行结果是

public class Test {

    public int div(int a, int b) {

        try {

            return a / b;

        }catch(Exception e){

            System.out.println(“Exception”);

        }catch(NullPointerException e){

            System.out.println(“ArithmeticException”);

        }

        catch (ArithmeticException e) {

            System.out.println(“ArithmeticException”);

        } finally {

            System.out.println(“finally”);

        }

        return 0;

    }

    public static void main(String[] args) {

        Test demo = new Test();

        System.out.println(“商是:” + demo.div(9, 0));

    }

}

D.

编译报错

2-24

对以下程序进行编译、运行结果是

abstract class Minebase {

abstract void amethod();

static int i;

}

public class Mine extends Minebase{

public static void main(String argv[]){

int[] ar = new int[5];

for(i = 0;i < ar.length;i++)

System.out.println(ar[i]);

}

}

C.

编译出错。

2-25

下列程序的运行结果是( )。

public class Test {

  public static void main(String[] args) {

    try {

      System.out.println("Welcome to Java");

      int i = 0;

      int y = 2 / i;

      System.out.println("Welcome to HTML");

    }

    finally {

      System.out.println("The finally clause is executed");

    }

  }

}

B.

Welcome to Java,下一行是 The finally clause is executed , 然后是错误信息.

2-26

下面哪个标识符不符合Java定义要求?

D.

100Book

2-27

下面( )不是Java的关键字。

C.

sizeof

2-28

int型public成员变量MAX_LENGTH,该值保持为常数100,则定义这个变量的语句是( )。

D.

public final int MAX_LENGTH = 100

2-29

Java 语言的特点不包括( )

(2分)

C.

多重继承

2-30

编译Java源文件和解释执行Java字节码文件的指令分别是什么?

D.

javac.exe和java.exe

2-31

在Java中,以下()类的对象是以键-值的方式存储对象。

C.

HashMap

2-32

要想在集合中保存没有重复的元素并且按照一定的顺序排序,可以使用以下()集合。

D.

TreeSet

2-33

getCustomerInfo()方法如下,try中可以捕获三种类型的异常,如果在该方法运行中产生了一个IOException,将会输出什么结果(   )。

public void getCustomerInfo() {

            try {

              // do something that may cause an Exception

            } catch (java.io.FileNotFoundException  ex){

                  System.out.print("FileNotFoundException!");

            } catch (java.io.IOException  ex){

                System.out.print("IOException!");

            } catch (java.lang.Exception  ex){

                 System.out.print("Exception!");

            }

}

A.

IOException!

2-34

下面代码运行结果是

public class Demo{

    public int add(int a,int b){

        try{

            return a+b;

        }catch(Exception e){

            System.out.println(“catch 语句块”);

        }finally{

            System.out.println(“finally 语句块”);

        }

        return 0;

    }

    public static void main(String[] args){

        Demo demo = new Demo();

        System.out.println(“和是:”+demo.add(9,34));

    }

}

B.

finally语句块 和是:43

2-35

下列程序的错误是( )

public class Test {

  public static void main (String[] args) {  

    try {

      System.out.println("Welcome to Java");

     }

  }

}

B.

有一个try块但没有catch块或finally块。

2-36

已知下列代码,如果方法oneMethod()运行异常,则下列哪个语句肯定不会被输出?

public void example(){

   try {

   oneMethod();

   System.out.println("condition1");

}catch(ArrayIndexOutOfBoundsException e) {

   System.out.println("condition2");

}catch(Exception e) {

   System.out.println("condition3");

}finally{

   System.out.println("condition4");

}

A.

condition1

2-37

将以下哪种方法插入行6是不合法的。(   ) 。

1.public  class  Test1 {

2.   public  float  aMethod(float a,float b) throws

3.   IOException {      }

4. }

5.public  class  Test2  extends  Test1{

6.

7.}

A.

float  aMethod(float  a,float  b){ }

2-38

下面的概念,哪个不是关于对象的多态性的体现。

B.

方法的继承

2-39

多态的表现形式有

A.

重写

2-40

class Person {

public void printValue(int i, int j) {//... }

public void printValue(int i){//... }

}

public class Teacher extends Person {

public void printValue() {//... }

public void printValue(int i) {//...}

public static void main(String args[]){

Person t = new Teacher();

t.printValue(10);

}
第10行语句将调用哪行语句?

D.

行7

2-41

如下代码的输出是( )。

public class Test {

  public static void main(String[] args) {

    new Person().printPerson();

    new Student().printPerson();

  }

}

class Student extends Person {

  private String getInfo() {

    return "Student";

  }

}

class Person {

  private String getInfo() {

    return "Person";

  }

  public void printPerson() {

    System.out.println(getInfo());

  }

}

A.

Person Person

2-42

已知类的继承关系如下:

class Employee;

class Manager extends Employee;

class Director extends Employee; 则以下语句哪个能通过编译? ( )。

A.

Employee e = new Manager();

2-43

设类B是类C的父类,下列声明对象x1的语句中不正确的是?

D.

C x1=new B( );

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