System.out.println("The three angles are: “+aa+” “+ab+” "+ac);
}
}
[](()4.7
================================================================
import java.util.Scanner;
public class disizhang {
public static void main(String[] args){
final double PI = 3.141592654;
Scanner input = new Scanner(System.in);
System.out.print("Enter the radius of the bounding circle: ");
double r = input.nextDouble();
double base = 0.1*PI;
System.out.println(“The coordinates of fibe points on the pentagon are”);
for(int i=0;i<5;i++)
{
System.out.printf(“(%.2f, %.2f)%n”,rMath.cos(base),rMath.sin(base));
base+=0.4*PI;
}
}
}
[](()4.8
================================================================
import java.util.Scanner;
public class disizhang {
public static void main(String[] args){
Scanner input = new Scanner(System.in);
System.out.print("Ent6er an ASCII code: ");
int num = input.nextInt();
char str = (char)num;
System.out.printf(“The character for ASCII code %d is %c”,num,str);
}
}
[](()4.9
================================================================
import java.util.Scanner;
public class disizhang {
public static void main(String[] args){
Scanner input = new Scanner(System.in);
System.out.print("Enter a character: ");
String jb = input.nextLine();
char str = jb.charAt(0);
int str2 = (int)str;
System.out.printf(“The Unicode for the character %c is %d”,str,str2);
}
}
[](()4.10
=================================================================
public class disizhang {
public static void main(String[] args)
{
//在原来代码中进行修改
int answer = input.nextInt()修改为：char answer = input.nextLine().charAt(0)
if(answer1)—>if(answer’Y’)
}
}
[](()4.11
=================================================================
import java.util.Scanner;
public class disizhang {
public static void main(String[] args){
System.out.print("Enter a decimal value (0 to 15): ");
Scanner input = new Scanner(System.in);
int num = input.nextInt();
if(num>=0&&num<=15){
if(num<10)
System.out.printf(“The hex value is %d”,num);
else
System.out.printf(“The hex value is %c”,‘A’+num-10);
}else
System.out.printf(“%d is an invalid input”,num);
}
}
[](()4.12
=================================================================
import java.util.Scanner;
public class disizhang {
public static void main(String[] args){
String[] bins = {“0”,“1”,“10”,“11”,“100”,“101”,“110”,“111”,“1000”,“1001”,“1010”,“1011”,“1100”,“1101”,“1110”,“1111”};
System.out.print("Enter a hex digit: ");
Scanner input = new Scanner(System.in);
char str = input.nextLine().charAt(0);
if(str>=‘0’&&str<=‘9’)
System.out.printf(“The binary value is %sn”,bins[str-‘0’]);
else if(str>=‘A’&&str<=‘F’)
System.out.printf(“The binary value is %sn”,bins[str-‘A’+10]);
else
System.out.printf(“%c is an invalid inputn”,str);
}
}
[](()4.13
=================================================================
import java.util.Scanner;
public class disizhang {
public static void main(String[] args){
Scanner input = new Scanner(System.in);
System.out.print("Enter a letter: ");
char str = input.nextLine().charAt(0);
if((str<=‘z’&&str>=‘a’)||(str<=‘Z’&&str>=‘A’))
{
