碼雲地址：https://gitee.com/bhma/codes/s57mefv2y0483irwtncb938

7-5 jmu-Java-03面向對象基礎-01-構造函數與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<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();
    }

}

設計思路：定義構造函數，調用子函數，輸入輸出。

運行結果：

7-6 集體評分

import java.util.Scanner;
import java.util.Arrays;   
 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{
    RT(int[] grade){
        super(grade);    
    }
    public double mark(){
        Arrays.sort(grade);      
        return (double)(grade[1]+grade[2]+grade[3])/3;    
    }
}

設計思路：輸入輸出，保留小數後兩位，利用數組調值。

運行結果：

7-7 程序填空題3

 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 {
    Son() {
        super(true);    
        System.out.println("Son‘s Constructor without parameter");
    }
    public void method() {
        System.out.println("Son‘s method()");
        super.method();
    }
}

設計思路：子類父類傳值，看懂程序。

運行結果：

7-8 求兩點之間距離

import java.util.*; 
import java.math.*; 
public class Main { 
  public static void main(String[] args) { 
    Scanner input = new Scanner(System.in); 
    double x1 = input.nextDouble(); 
    double y1 = input.nextDouble(); 
    double x2 = input.nextDouble(); 
    double y2 = input.nextDouble(); 
    System.out.println(String.format("%.2f", Math.sqrt((x1 - x2)*(x1 - x2) + (y1 - y2)*(y1 - y2))) ); 
    
  } 
  
}

設計思路：兩個坐標，構造函數。

運行結果：

總結：這次考核讓我認清了自己，好多東西不會，4道題也只做上了一道，還有子類父類和數組那塊太模糊了， 還有可能我的思路不是很清晰，想程序時總走彎路，老多的地方不會了，要不就是自己給自己挖個坑。爭取以後好好努力把，加油！

第二次過程性考核！