java大学实用教程(第三版)课后答案

习题解答 第一章 作业题 1． public class Hello{ public static void main (String args[ ]){ System.out.pintln(“早上好，good Morning”); } } 2． import java.applet.*; import java.awt.*; public class Boy extends Applet { public void paint(Graphics g) { g.setColor(Color.blue); g.drawString("你好,hello",12,30); } } 第二章 作业题 1． public class ZuoYe2_1{ public static void main (String args[ ]){ char c='а'; System.out.println("字母"+c+"在 unicode 表中的顺序位置:"+(int)c); System.out.println("字母表："); while(c<='я'){ System.out.print(" "+c); c=(char)(c+1); } } } 2． import java.util.*; public class ZuoYe2_2{ public static void main (String args[ ]){ Scanner reader=new Scanner(System.in); long chengji=1; int m=0; while(reader.hasNextInt()){ int x=reader.nextInt(); m=m+1; chengji=chengji*x; } System.out.println(m+"个数的乘积为"+chengji); } } 第三章 作业题 1． import java.util.*; public class ZuoYe3_1{ public static void main (String args[ ]){ Scanner reader=new Scanner(System.in); double y=0,x=0; x=reader.nextDouble(); if(x<0) y=-1+2*x; else if(x==0) y=-1; else if(x>0) y=-1+3*x; System.out.println(y); } } 2． public class ZuoYe3_2{ public static void main(String args[]){ int sum=0,m=3,n=7,a=1; while(a<=1000){ if(a%m==0&&a%n==0) sum=sum+a; a++; } System.out.println("sum="+sum); } } 3． public class ZuoYe3_3 { public static void main(String args[]) { long sum=0,a=8,item=a,n=10,i=1; for(i=1;i<=n;i++) { sum=sum+item; item=item*10+a; } System.out.println(sum); } } 4． public class ZuoYe3_4 { public static void main(String args[]) { double sum=0,a=1,b=1,fuhao=1,item=a/b; int i=1; while(i<=1000) { sum=sum+fuhao*item; i++; fuhao=fuhao*(-1); b=b+2; item=a/b; } System.out.println("sum="+sum); } } 5． public class ZuoYe3_5 { public static void main(String args[]) { double sum=0,...