Java第二次作业

public class Test2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        int r=5;
        double s=3.14*r*r;
        System.out.println("圆的面积为S="+s);

    }

}

 

public class Test2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        double hua=50;
        double shua=50-32;
        shua=shua*5.0/9.0;
        System.out.println(hua+"华氏度="+shua+"摄氏度");
        double she=30;
        double hshe=she*9.0/5.0+32;
        System.out.println(she+"摄氏度="+hshe+"华氏度");
    }

}

　　

 

public class Test2 {

/**
* @param args
*/
public static void main(String[] args) {
int a=5;
int b=8;
int c;
System.out.println("a="+a+"\tb="+b);
c=a;
a=b;
b=c;
System.out.println("a="+a+"\tb="+b);

}

}

public class Test2 {

/**
* @param args
*/
public static void main(String[] args) {
int a=12345;
System.out.println("a="+a);
a=a/100*100;
System.out.println("a="+a);
}

}

 

public class Test2 {

/**
* @param args
*/
public static void main(String[] args) {
int a=456;
int ge=a%10;
int shi=a%100/10;
int bai=a%1000/100;
int sum=ge+shi+bai;
System.out.println(sum);

}

}

 

public class Test2 {

/**
* @param args
*/
public static void main(String[] args) {
char x='H';
char d='f';
System.out.println("x是"+x+"\t d是"+d);
x=(char)(x+32);
d=(char)(d-32);
System.out.println("x是"+x+"\t d是"+d);


}

}