代码改变世界

第二次过程性考核

2018-10-14 19:16  QM!  阅读(756)  评论(2)  编辑  收藏  举报

码云仓库链接：https://gitee.com/QM0829/codes

7-5 jmu-Java-03面向对象基础-01-构造函数与toString （3 分）

定义一个有关人的Person类，内含属性：
String name、int age、boolean gender、int id，所有的变量必须为私有(private)。 注意：属性顺序请严格按照上述顺序依次出现。

1.编写无参构造函数：

  • 打印"This is constructor"。
  • 将name,age,gender,id按照name,age,gender,id格式输出

2.编写有参构造函数

依次对name,age,gender赋值。

3.覆盖toString函数：

按照格式：类名 [name=, age=, gender=, id=]输出。建议使用Eclipse自动生成.

4.对每个属性生成setter/getter方法

5.main方法中

  • 首先从屏幕读取n，代表要创建的对象个数。
  • 然后输入n行name age gender , 调用上面2编写的有参构造函数新建对象。
  • 然后将刚才创建的所有对象逆序输出。
  • 接下来使用无参构造函数新建一个Person对象，并直接打印该对象。

输入样例:

3
a 11 false
b 12 true
c 10 false

输出样例:

Person [name=c, age=10, gender=false, id=0]
Person [name=b, age=12, gender=true, id=0]
Person [name=a, age=11, gender=false, id=0]
This is constructor
null,0,false,0
Person [name=null, age=0, gender=false, id=0]

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<per.length; 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();
    }

}
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<per.length; 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();
    }

}

 

7-6 集体评分 （5 分）

程序填空题。请补充以下代码，完成题目要求。（注意：需要提交完整代码） 有一个团队由5个人组成。他们每个人给指导老师一个分数，去掉最高分，去掉最低分，剩下的3个分数的平均分就是该团队对指导老师的评分。

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
                Scanner in = new Scanner(System.in);
                int[] grade = new int[5];
                for(int i=0; i<grade.length; i++){
                      grade[i] = in.nextInt();
                 }       

                RR rr = new RT(grade);
                double dd = rr.mark();
                System.out.printf("%.2f",dd);
    }
}
abstract class RR{
   int[] grade;
   public RR(int[] grade){
      this.grade = grade;
   }
   public abstract double mark();
}
class RT extends RR{

}

输入格式:

在一行中给出5个不超过10的正整数（从小到大排列）。

输出格式:

输出集体评分，保留小数点后两位。

输入样例:

1 2 4 6 9

 
 
import java.util.Scanner;

abstract class RR{
   int[] grade;
   public RR(int[] grade){
      this.grade = grade;
   }
   public abstract double mark();
}
class RT extends RR{
    
    
    public RT(int[] grade) {
        super(grade);
    }

    public double mark(){
        double x = (grade[1]+grade[2]+grade[3])/3;
        return x;
    }
}
public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
         @SuppressWarnings("resource")
        Scanner in = new Scanner(System.in);
         int[] grade = new int[5];
         for(int i=0; i<grade.length; i++){
               grade[i] = in.nextInt();
          }       

         RR rr = new RT(grade);
         double dd = rr.mark();
         System.out.printf("%.2f",dd);
    }

}
7-7 程序填空题3 （5 分）

参照输出样例补全以下程序，使程序输出结果与输出样例一致。

  public class Main {
	public static void main(String[] args) {
		Son son = new Son();
		son.method();
	}
}

class Parent {
	Parent() {
		System.out.println("Parent's Constructor without parameter");
	}

	Parent(boolean b) {
		System.out.println("Parent's Constructor with a boolean parameter");
	}

	public void method() {
		System.out.println("Parent's method()");
	}
}

class Son extends Parent {
	//补全本类定义
}

输入格式:

无

输出格式:

无

输入样例:

输出样例:

Parent's Constructor with a boolean parameter
Son's Constructor without parameter
Son's method()
Parent's method()
class Parent {
    Parent() {
        System.out.println("Parent's Constructor without parameter");
    }

    Parent(boolean b) {
        System.out.println("Parent's Constructor with a boolean parameter");
    }

    public void method() {
        System.out.println("Parent's method()");
    }
}

class Son extends Parent {
    //补全本类定义
    Son(){
        super(true);//调用父类含有参数的构造方法
        System.out.println("Son's Constructor without parameter");
    }
    public void method() {
        System.out.println("Son's method()");
        super.method();//调用父类的method方法
    }
}
public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Son son = new Son();
        son.method();
    }

}


7-8 求两点之间距离 （20 分）








定义一个Point类，有两个数据成员：x和y, 分别代表x坐标和y坐标，并有若干成员函数。 定义一个函数Distance(), 用于求两点之间的距离。


输入格式:


输入有两行： 第一行是第一个点的x坐标和y坐标； 第二行是第二个点的x坐标和y坐标。


输出格式:


输出两个点之间的距离，保留两位小数。


输入样例:


0 9 3 -4


输出样例:


13.34




import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        @SuppressWarnings("resource")
        Scanner reader = new Scanner(System.in);
        int x1 = reader.nextInt();
        int y1 = reader.nextInt();
        int x2 = reader.nextInt();
        int y2 = reader.nextInt();
        Point spot = new Point(x1, y1);    
        Point spot2 = new Point(x2, y2);
        double m = Point.Distance(spot, spot2);    
        System.out.printf("%.2f", m);    

    }
}

class Point {
    double x;
    double y;

    public Point(double x, double y) {
        this.x = x;
        this.y = y;
    }

    public static double Distance(Point a, Point b) {
        double c = 0;
        double i = Math.pow((a.x - b.x), 2);
        double j = Math.pow((a.y - b.y), 2); 
        c = Math.sqrt(i + j);    
        return c;
    }
}






import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        @SuppressWarnings("resource")
        Scanner reader = new Scanner(System.in);
        int x1 = reader.nextInt();
        int y1 = reader.nextInt();
        int x2 = reader.nextInt();
        int y2 = reader.nextInt();
        Point spot = new Point(x1, y1);    
        Point spot2 = new Point(x2, y2);
        double m = Point.Distance(spot, spot2);    
        System.out.printf("%.2f", m);    

    }
}

class Point {
    double x;
    double y;

    public Point(double x, double y) {
        this.x = x;
        this.y = y;
    }

    public static double Distance(Point a, Point b) {
        double c = 0;
        double i = Math.pow((a.x - b.x), 2);
        double j = Math.pow((a.y - b.y), 2); 
        c = Math.sqrt(i + j);    
        return c;
    }
}