第一次作业

1、定义圆的半径，求面积。

package test1;
public class java {
public static void main(String[] args) {
// TODO Auto-generated method stub
double r=8;
double area=3.14*r*r;
System.out.println("半径是8，求圆的面积是"+area);
}
}

 

 

2、华氏温度和摄氏温度相互转换，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。

 

1 public class Main {
 2     public static void main(String[] args) {
 3         System.out.println("将华氏度转化为摄氏度");
 4         double temper1=56;
 5         double temper2=(temper1-32)*5/9;
 6         System.out.println("摄氏度为"+temper2);
 7         System.out.println("将摄氏度转化为华氏度");
 8         double temper3=23;
 9         double temper4=temper3*9/5+32;
10         System.out.println("华氏度为"+temper4);
11 
12     }
13 }

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。

age test1;
public class helloworld {
public static void main(String[] args) {
// TODO Auto-generated method stub
int a=4;
int b=5;
int c;
System.out.println("a="+a+"\tb"+b);
System.out.println("转化后");
c=a;
a=b;
b=c;
System.out.println("a="+a+"\tb="+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。

package test1;
public class zuoye {
public static void main(String[] args) {
// TODO Auto-generated method stub
int s=12234,s1;
s1=s/100*100;
System.out.println(s1);
}
}

5、输入一个0~1000的整数，求各位数的和。

package test1;
public class java {
public static void main(String[] args) {
// TODO Auto-generated method stub
int a=345;
int ind=a/1000;
int ten=a%1000/100;
int b=a%100/10;
int c=a%10;
int sum=ind+ten+b+c;
System.out.println(sum);
}
}

6、定义一个任意的大写字母A~Z,转换成小写字母

package test1;
import java.util.Scanner;
public class java {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input=new Scanner(System.in);
System.out.println("输入一个大写字母");
char c=input.next().charAt(0);
char xiaoxie=(char)(c+32);
System.out.println("对应的小写是"+xiaoxie);
}
}

 

7.定义一个任意的小写字母a~z，转换为大写字母

package test1;
import java.util.Scanner;
public class java {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input=new Scanner(System.in);
System.out.println("输入一个小写字母");
char c=input.next().charAt(0);
char daxie=(char)(c-32);
System.out.println("对应的大写是"+daxie);
}
}

package test1;

publicclass java {

publicstaticvoid main(String[] args) {

// TODO Auto-generated method stub

doubler=8;

doublearea=3.14*r*r;

System.out.println("半径是8，求圆的面积是"+area);

}

}

 

2.

package test1;

publicclass zuotian {

publicstaticvoid main(String[] args) {

// TODO Auto-generated method stub

floatf;

floatc;

f=72;

c=f/9*5-32;

System.out.println(c);

c=56;

f=c*9/5+32;

System.out.println(f);

}

}

 

 

3．age test1;

publicclass helloworld {

publicstaticvoid main(String[] args) {

// TODO Auto-generated method stub

inta=4;

intb=5;

intc;

System.out.println("a="+a+"\tb"+b);

System.out.println("转化后");

c=a;

a=b;

b=c;

System.out.println("a="+a+"\tb="+b);

}

}

 

 

3.

package test1;

publicclass helloworld {

publicstaticvoid main(String[] args) {

// TODO Auto-generated method stub

inta=2, b=3;

a=a+b;

b=a-b;

a=a-b;

System.out.println(a);

System.out.println(b);

}

}

 

4.

package test1;

publicclass zuoye {

publicstaticvoid main(String[] args) {

// TODO Auto-generated method stub

ints=12234,s1;

s1=s/100*100;

System.out.println(s1);

}

}

 

5.

 

package test1;

publicclass java {

publicstaticvoid main(String[] args) {

// TODO Auto-generated method stub

inta=345;

intind=a/1000;

intten=a%1000/100;

intb=a%100/10;

intc=a%10;

intsum=ind+ten+b+c;

System.out.println(sum);

}

}

 

6.

package test1;

import java.util.Scanner;

publicclass java {

publicstaticvoid main(String[] args) {

// TODO Auto-generated method stub

Scanner input=new Scanner(System.in);

System.out.println("输入一个大写字母");

charc=input.next().charAt(0);

charxiaoxie=(char)(c+32);

System.out.println("对应的小写是"+xiaoxie);

}

}

 

7.

package test1;

import java.util.Scanner;

publicclass java {

publicstaticvoid main(String[] args) {

// TODO Auto-generated method stub

Scanner input=new Scanner(System.in);

System.out.println("输入一个小写字母");

charc=input.next().charAt(0);

chardaxie=(char)(c-32);

System.out.println("对应的大写是"+daxie);

}

}