参考链接： Java中的Scanner和nextChar()

JAVA语言程序设计（基础篇）第十版课后题答案 第一章 第二题 /** 

 Created by ysy on 2018/7/6. */ public class text2 { public static void main(String[] args){ for(int i = 0; i < 5; i++) System.out.println(“Welcome to Java”); }  

} 

第三题 /** 

Created by ysy on 2018/7/6. */ public class text3 { public static void main(String[] args){ System.out.println(" J A V V A"); System.out.println(" J A A V V A A"); System.out.println(“J J AAAAA V V AAAAA”); System.out.println(" JJ A A V A A"); } } 第四题 import java.util.Scanner; 

/** 

 Created by ysy on 2018/7/6. *对输入数据求解一次方，平方，三次方 */ public class text4 { public static void main(String[] args){  Scanner input = new Scanner(System.in);

 char[] temp = new char[10];

 int num;

 for(int i = 0; i < 5; ++i){

     String Stemp;

     System.out.println("请输入数据：");

     Stemp = input.next();

     temp = Stemp.toCharArray();

     if(temp[0] >= 'a' && temp[0] <= 'z'){

         System.out.println(temp[0]+"    "+temp[0]+"^2    " + temp[0] + "^3");

     }

     else if(temp[0] >= '0' && temp[0] <= '9'){

         num = temp[0] - '0';

         System.out.println(num+"    "+(int)Math.pow(num, 2)+"    "+(int)Math.pow(num, 3));

     }

 

 }

 } }  

第七题 import java.util.Scanner; 

/** 

 Created by ysy on 2018/7/6. *对输入数据求解一次方，平方，三次方 */ public class text4 { public static void main(String[] args){  Scanner input = new Scanner(System.in);

 char[] temp = new char[10];

 int num;

 for(int i = 0; i < 5; ++i){

     String Stemp;

     System.out.println("请输入数据：");

     Stemp = input.next();

     temp = Stemp.toCharArray();

     if(temp[0] >= 'a' && temp[0] <= 'z'){

         System.out.println(temp[0]+"    "+temp[0]+"^2    " + temp[0] + "^3");

     }

     else if(temp[0] >= '0' && temp[0] <= '9'){

         num = temp[0] - '0';

         System.out.println(num+"    "+(int)Math.pow(num, 2)+"    "+(int)Math.pow(num, 3));

     }

 

 }

 } }  

第八题 

/** 

 Created by ysy on 2018/7/6. */ public class text8 { static double pi=3.14; public static void main(String arg[]){  double r=5.5;

 double a=getLength(r);

 double b=getArea(r);

 System.out.println("周长:"+a);

 System.out.println("面积:"+b);

 } public static double getLength(double r){ return 2rpi; } public static double getArea(double r){ return rrpi; }  

} 

第九题 /** 

Created by ysy on 2018/7/6. */ public class text9 { public static void main(String[] arg){ double a=14/1.6; double t=45.5/60; double v=a/t; System.out.println(“速度”+v); } } 

第十一题 

/** 

Created by ysy on 2018/7/6. / public class text11 { public static void main(String arg[]){ int now_num=312032486; int time=365246060; int spring=time/7; int die=time/13; int move=time/45; int num=now_num+spring-die+move; System.out.println(num); } } 

第十二题 

/** 

 Created by ysy on 2018/7/6. / public class text12 { public static void main(String[] arg){ double a=3.4; double b=50.24; double c=2.1; double d=0.55; double e=44.5; double f=5.9; double x=(ed-bf)/(ad-bc); double y=(af-ec)/(ad-b*c); System.out.println(“x:”+x); System.out.println(“y:”+y); } }