学习日志——2019/07/01

java语言基础

• 计算平均数(输入数字以-1结束)

package eg1;

import java.util.Scanner;

public class avg {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner in =new Scanner(System.in);
		int number;
		int sum=0;
		int count =0;
		number=in.nextInt();
		while(number!=-1)
		{
			sum=sum+number;
			count=count +1;
			number=in.nextInt();
		}
		if(count>0)
		{
			System.out.println("平均数="+(double)sum/count);;
		}
	}
}

do while：

package eg1;

import java.util.Scanner;

public class avg {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner in =new Scanner(System.in);
		int number;
		int sum=0;
		int count =0;
//		number=in.nextInt();
//		while(number!=-1)
//		{
//			sum=sum+number;
//			count=count +1;
//			number=in.nextInt();
//		}
		do {
			number=in.nextInt();
			sum=sum+number;
			count=count +1;
		}while(number!=-1);
		if(count>0)
		{
			System.out.println("平均数="+(double)sum/count);;
		}
	}
}

• 循环条件不是跳出循环，而是让循环继续进行的条件
  猜数小游戏

package eg1;

import java.util.Scanner;

public class cshugame {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner in =new Scanner(System.in);
		int number=(int)(Math.random()*100+1);//[0,1)-->[0,100)-->[1,100]
		int a;//用户输入的数
		int count =0;//猜的次数
		do {
			a=in.nextInt();
			count=count+1;
			if(a>number)
			{
				System.out.println("偏大");
			}
			else if(a<number)
			{
				System.out.println("偏小");
			}				
		}while(a!=number);
		System.out.println("恭喜你猜对了，你猜了"+count+"次");
	}
}

对整数分解

package eg1;

import java.util.Scanner;

public class fj {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner in =new Scanner(System.in);
		int number;
		number=in.nextInt();
		int result=0;
		do{
			int digit=number %10;
			result=result*10+digit;
			System.out.print(digit);
			number=number/10;		
		}while(number>0);
		System.out.println();
		System.out.println(result);
	}
}