启发一下. import java.io.*; import java.lang.*;public class Area { public Area() { } public static void main(String args[]) throws Exception { InputStreamReader inputstreamreader = new InputStreamReader(System.in); BufferedReader bufferedreader = new BufferedReader(inputstreamreader); System.out.print("Enter the radius: "); String s = bufferedreader.readLine(); Double double1 = new Double(s); double d = double1.doubleValue(); System.out.println("The area of a circle of radius " + d); double d1 = Math.PI * d * d; System.out.println(" is " + d1); } }
for(int i=0;i<b.length;i++)
{
if(b[i]<0)
byte=255+b[i];
else
byte=b[i];
}
只有象int,float这样的类型才有数据表示范围的限制。如byte的值可以为10000000,如果你把它转为int,则int值表示-128,取第一位为符号位,补码表示。
if(b[i]<0)
byte= (b[i]&0x7f)|0x80;
else
byte=b[i];
import java.lang.*;public class Area { public Area() {
} public static void main(String args[]) throws Exception {
InputStreamReader inputstreamreader = new InputStreamReader(System.in);
BufferedReader bufferedreader = new BufferedReader(inputstreamreader);
System.out.print("Enter the radius: ");
String s = bufferedreader.readLine();
Double double1 = new Double(s);
double d = double1.doubleValue();
System.out.println("The area of a circle of radius " + d);
double d1 = Math.PI * d * d;
System.out.println(" is " + d1);
}
}