第三周作业

1.定义圆的半径求面积

package iii;

import java.util.Scanner;

public class faa {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input=new Scanner(System.in);
        System.out.println("请输入圆的半径");
        int r=input.nextInt();
        double Π=3.14;
        System.out.println("圆的面积为:"+Π*r*r);

    }

}

 

 2.华氏度和摄氏度的互相转换

package iii;

public class faa {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
         double h=10;
            double s;
            s=(h-32)*5/9;
            System.out.println("华氏度是:"+h+"摄氏度是:"+s);
            s=20;
            h=s*9/5+32;
            System.out.println("摄氏度是:"+s+"华氏度是:"+h);
    }

}

 

 3.已知a,b为整形变量，写出将a，b两个变量中的值互换的程序

package iii;

public class faa {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a=7;
        int b=9;
        int c=a;
        a=b;
        b=c;
        System.out.println("a的值是:"+a+"\nb的值是:"+b);
    }

}

 

 4.定义一个任意五位数，将他保留到百位，无需四舍五入

package iii;

public class faa {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a=99999;
        a=a%1000;
        System.out.println("a的值是:"+a);
    }

}

 

 5.输入一个0~1000的整数求各位的和

package iii;

import java.util.Scanner;

public class faa {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input=new Scanner(System.in);
        System.out.println("输入一个0~1000的整数");
        int a=input.nextInt();
        int b,c,d,sum;
        b=a/100;
        c=a%100/10;
        d=a%10;
        sum=b+c+d;
        System.out.println("该数各位数的和是:"+sum);

    }

}

 

 6.定义一个大写字母A-Z，转化为小写字母

package iii;

public class faa {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
         int x='B';
            char c=(char) (x+32);
            System.out.println("小写字母为："+c);
    }

}

 

 7.输入任意一个小写字母，转化为大写字母

package iii;

import java.util.Scanner;

public class faa {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
         Scanner input=new Scanner(System.in);
         System.out.println("请输入一个小写字母");
         char b=input.next().charAt(0);
         char daxie=(char)(b-32);
         System.out.println("对应大写字母为"+daxie);
         
        
    }

}