第一次作业

Posted 2023-03-23 Berial127

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1. 定义圆形半径，求面积。int r =4;

package mjkjkmkj;

public class njknjknkj
    public static void main(String[] args)
        double r = 4;
        double mian = 0;
        mian = r * r * 3.14;
        System.out.println("园的面积为" + mian);
   

 

 2.     华氏温度和摄氏温度互相转换，从华氏度变成摄氏度你只要减去32，乘以5再除以9就行了，将摄氏度转成华氏度，直接乘以9，除以5，再加上32即行。

3.  package mjkjkmkj;

import java.util.Scanner;

public class njknjknkj 

    public static void main(String[] args) 

        Scanner sc = new Scanner(System.in);

        System.out.println("请输入（1/0）");

        System.out.println("1.输入摄氏度  2.输入华氏度"  );

        int i = sc.nextInt();

        if(i == 1) 

            System.out.println("请输入摄氏度温度：");

            double s = sc.nextDouble();

            double h = s * 9 / 5 + 32;

            System.out.println( "摄氏度"+ s + "温度转换为摄氏温度为" + h + "度");

        

        if(i == 0) 

            System.out.println("请输入华氏温度：");

            double h = sc.nextDouble();

            double s = (h - 32) * 5 / 9;

            System.out.println( "华氏摄氏度"+ h + "温度转换为摄氏温度为" + s + "度");

        

    

 

 

3. 已知a,b均是整型变量，写出将a,b两个变量中的值互换的程序。

package mjkjkmkj;

import java.util.Scanner;

public class njknjknkj 

    public static void main(String[] args) 

        int a = 3;

        int b = 8;

        int temp = 0;

        temp = a;

        a = b;

        b = temp;

        System.out.println("交换过后" + ",a =" + a + ",b =" + b);

    

 

4定义一个任意的5位整数，将它保留到百位，无需四舍五入（知识点：变量和运算符综合应用）

  package mjkjkmkj;

import java.util.Scanner;

public class njknjknkj 

    public static void main(String[] args) 

        int a = 23288;

        a = a /10 /10;

        System.out.println(a);

    

 

5，.输入一个0～1000的整数，求各位数的和，例如345的结果是3+4+5＝12注：分解数字既可以先除后模也可以先模后除（知识点：变量和运算符综合应用）

public class njknjknkj 

    public static void main(String[] args) 

        Scanner sc = new Scanner(System.in);

        System.out.println("请输入一个0 ~ 1000的整数");

        int shu = sc.nextInt();

        int ge = shu % 10;

        int shi = shu % 100 / 10;

        int bai = shu / 100  % 10;

        int qian = shu / 1000;

        System.out.println("个位是" + ge);

        System.out.println("十位是" + shi);

        System.out.println("百位是" + bai);

        System.out.println("千位是" + qian);

    

 

6. 定义一个任意的大写字母A~Z，转换为小写字母（知识点：变量和运算符综合应用） 

package mjkjkmkj;

import java.util.Scanner;

public class njknjknkj 

    public static void main(String[] args) 

                Scanner reader=new Scanner(System.in);

                char c=\'G\',x;

                x=(char)(c+32);

                System.out.println("小写字母是："+x);

            



    

 

 

7. 输入一个任意的小写字母a~z，转换为大写字母

package mjkjkmkj;

import java.util.Scanner;

public class njknjknkj 

    public static void main(String[] args) 

        Scanner sc = new Scanner(System.in);

        String s = sc.next();

        char zi = s.charAt(0);

        char xzi = (char)(zi - 32);

        System.out.println(xzi);