Ming solution JAVA chapter answers

Exercise 2-1

Compile error, you can not run.

Exercise 2-2

Package candle1220; 



    class Nightwatch { 

        public  static  void main (String [] args) {
             int X, Y, Z; 
             X = 22 is ; 
             Y = 23 is ; 
             Z = 35 ; 
            the System.out .println ( "total value is" + (x + y + z) + "average value" + (X + Y + Z) /. 3 ); 
    } 
    }

 Exercise 2-3

Package candle1220; 

Import java.util.Scanner; 

    class Nightwatch { 

        public  static  void main (String [] args) { 
            Scanner stdin = new new (the System .in) Scanner;
             int X; 
            the System .out .print ( "integer:" ) ; 
            X = stdIn.nextInt (); 
            the System.out .println ( "input value is" + X); 
                
    } 
    }

Exercise 2-4

Package candle1220; 

Import java.util.Scanner; 

    class Nightwatch { 

        public  static  void main (String [] args) { 
            Scanner stdin = new new (the System .in) Scanner;
             int X; 
            of System.out.print ( "integer:" ) ; 
            X = stdIn.nextInt (); 
            System.out.println ( "10 is a value obtained by adding" + (X + 10 )); 
            System.out.println ( "10 is a value obtained by subtracting" + (x-10 ));                 
    } 
    }
                        

Exercise 2-5

Package candle1220; 

Import java.util.Scanner; 

    class Nightwatch { 

        public  static  void main (String [] args) { 
            Scanner stdin = new new (the System .in) Scanner;
             Double x, Y; 
            of System.out.print ( "value of x : " ); 
            X = stdIn.nextDouble (); 
            of System.out.print ( " Y value: " ); 
            Y = stdIn.nextDouble (); 
            System.out.println ( " total value is "+ (X + Y) ); 
            System.out.println ( "average is" + (xy) / 2);                
            
    }
    }
                        

Exercise 2-6

package candle1220;

import java.util.Scanner;

    class Nightwatch{

        public static void main(String[] args) {
            Scanner stdIn=new Scanner(System .in);
            double x,y;
            System.out.println("求三角形的面积。");
            System.out.print("底:");
            x=stdIn.nextDouble();
            System.out.print("高:");
            y=stdIn.nextDouble();
            System.out.println("面积是"+(x*y)/2);
            
    }
    }
                        

Exercise 2-7

package candle1220;

import java.util.Scanner;
import java.util.Random;

    class Nightwatch{

        public static void main(String[] args) {
            Scanner stdIn=new Scanner(System .in);
            Random rand=new Random();
        int lucky=rand.nextInt(8);
            System.out.print("随机数:"+(lucky+1));
            
    }
    }
                        

package candle1220;

import java.util.Scanner;
import java.util.Random;

    class Nightwatch{

        public static void main(String[] args) {
            Scanner stdIn=new Scanner(System .in);
            Random rand=new Random();
        int lucky=rand.nextInt(9);
            System.out.print("随机数:"+(lucky-9));
            
    }
    }
                        

Exercise 2-8

Package candle1220; 

Import java.util.Scanner;
 Import java.util.Random; 

    class Nightwatch { 

        public  static  void main (String [] args) { 
            Scanner stdin = new new Scanner (.in the System); 
            the Random RAND = new new the Random ();
             int Lucky = (rand.nextInt (. 11) -5 ); 
            of System.out.print ( "integer:" );
             int X = stdIn.nextInt (); 
            System.out.println ( "generates the value range of ± 5 the random number is "+ (X + Lucky)); 
            
        
    } 
    }
                        

Exercise 2-9

package candle1220;

import java.util.Scanner;
import java.util.Random;

    class Nightwatch{

        public static void main(String[] args) {
            Scanner stdIn=new Scanner(System.in);
            Random rand=new Random();
            double lucky=rand.nextDouble();
            System.out.print("随机数:"+lucky);
                
        
    }
    }
                        

package candle1220;

import java.util.Scanner;
import java.util.Random;

    class Nightwatch{

        public static void main(String[] args) {
            Scanner stdIn=new Scanner(System.in);
            Random rand=new Random();
            double lucky=10*rand.nextDouble();
            System.out.print("随机数:"+lucky);
                
        
    }
    }
                        

package candle1220;

import java.util.Scanner;
import java.util.Random;

    class Nightwatch{

        public static void main(String[] args) {
            Scanner stdIn=new Scanner(System.in);
            Random rand=new Random();
            double lucky=(2*rand.nextDouble()-1);
            System.out.print("随机数:"+lucky);
                
        
    }
    }
                        

Exercise 2-10

package candle1220;

import java.util.Scanner;

    class Nightwatch{

        public static void main(String[] args) {
            Scanner stdIn=new Scanner(System.in);
            String s1="柴田";
            String s2="望洋";
            System.out.println("姓:"+s1);
            System.out.println("名:"+s2);
            System.out.println("你好"+s2+s1+"先生。");
            
            
                
    }
    }