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【java】定义课程信息;继承和组合练习

作者:互联网

分析

初分析:
父类(课程信息类):三个变量(编号、名称、以及学生成绩)、构造方法默认以及全选的、方法get个set类和display。
子类(对父类的统计及分析):构造方法(关键字super()),方法(平均值、最大最小值以及分布律)

设计

父类(课程信息类):

package HOME8;

public class Course_infor {
	private String number;
	private String name;
	public int[] grades;
	
	public Course_infor() {
		
	}

	public Course_infor(String number, String name, int[] grades ) {
		
		this.number = number;
		this.name = name;
		this.grades = grades;
	}

	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 int[] getGrades() {
		return grades;
	}

	public void setGrades(int[] grades) {
		this.grades = grades;
	}
	
	public void display() {
		System.out.println("课程编号:"+number+"\n"+ "课程名称:"+name+"\n");
	}


	

}

子类(对父类的统计及分析)

package HOME8;


public class Statistics extends Course_infor {
	int sum = 0,Max,Min;
	int[] DL = new int[11];
	
	public Statistics() {
		
	}
	public Statistics(String number, String name, int[] grades ) {
		super(number,name,grades);
		Min = grades[0];
		Max = grades[0];
		
	}

	public void average() {
		for(int i = 0;i<grades.length;i++) {
			
			sum += grades[i];
		}
		System.out.println("平均值:"+(double)sum/grades.length+"\n"); 
		
	}
	public void Maxgrades() {
		for(int i = 0;i<grades.length;i++) {
					
					if(Max<grades[i])
					{
						Max = grades[i];
					}
				}
		
		System.out.println("最大值:"+Max+"\n"); 
	}
	public void Mingrades() {
		for(int i = 0;i<grades.length;i++) {
					
					if(Min>grades[i])
					{
						Min = grades[i];
					}
				}
		
		System.out.println("最小值:"+Min+"\n"); 
	}
	public void DL() {
		for(int i = 0;i<grades.length;i++) {
			DL[grades[i]/10]++;
		}
		
	  for(int i=0;i<11;i++) {
		  System.out.printf("%d~%d:",10*i,10*(i+1));
		  for(int j = 0;j<DL[i];j++) {
			  System.out.printf("*");
		  }
		  System.out.println();
			  
	  }
	  
		
		
	}
	
	

}

测试

测试

点击查看代码
package HOME8;

public class test {

	public static void main(String[] args) {
		Course_infor a = new Course_infor("a","软件工程实践",new int[]{12,14,1,2,21,22,33,44,55,66,77,88,99});
		a.display();
		Statistics b = new Statistics("a","软件工程实践",new int[]{12,14,1,2,21,22,33,44,55,66,77,88,99});
		b.average();
		b.Maxgrades();
		b.Mingrades();
		b.DL();
		
		

	}

}

标签:java,name,int,练习,number,grades,课程,public,String
来源: https://www.cnblogs.com/zhujiaozhu/p/15385273.html