java第一次作业

1. package ccc;

 

import java.util.Scanner;

 

public class ccc {

 

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner in=new Scanner(System.in);

System.out.println("输入半径");

int a=3;

    double b=a*a*3.14;

    System.out.println("面积为"+b);

 

}

 

}

　　

　　

 

 

 

 

2. package ccc;

 

import java.util.Scanner;

 

public class ccc {

 

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner in=new Scanner(System.in);

System.out.println("输入华氏温度");

double a=in.nextDouble();

    double b=(a-32)*5/9;

    System.out.println("摄氏温度为"+b);

    System.out.println("输入摄氏温度");

double c=in.nextDouble();

    double d=c*9/5+32;

    System.out.println("华氏温度为"+d);

 

}

 

}

　　

　　

 

 

 

3. package ccc;

 

import java.util.Scanner;

 

public class ccc {

 

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner in=new Scanner(System.in);

System.out.println("输入a");

int a=in.nextInt();

System.out.println("输入b");

int b=in.nextInt();

int c;

c=a;

a=b;

b=c;

    System.out.println("a为"+a);

    System.out.println("b为"+b);

}

 

}

　　

 

 

 

4. package ccc;

 

import java.util.Scanner;

 

public class ccc {

 

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner in=new Scanner(System.in);

System.out.println("输入一个五位数");

int a=35657;

int b=a%100;

int c=a-b;

    System.out.println("保留到百位为"+c);

}

 

}

　　

 

 

 

5. package ccc;

 

import java.util.Scanner;

 

public class ccc {

 

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner in=new Scanner(System.in);

System.out.println("输入一个0-1000的数");

int a=in.nextInt();

int b,c,d,e;

b=a/100;

c=a%100/10;

d=a%10;

e=b+c+d;

    System.out.println("和为"+e);

}

 

}

　　

 

 

 

6. package ccc;

 

import java.util.Scanner;

 

public class ccc {

 

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner in=new Scanner(System.in);

        char a='A';

        char b=(char)(a+32);

        System.out.println("小写为"+b);

        

}

 

}

　　

 

 

 

7. package ccc;

 

import java.util.Scanner;

 

public class ccc {

 

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner in=new Scanner(System.in);

System.out.println("请输入一个小写字母");

        char a=in.next().charAt(0);

        char b=(char)(a-32);

        System.out.println("大写为"+b);

        

}

 

}