Java流程控制语句

实验二 Java流程控制语句一、实验时间和地点时间：2010年10月18日地点：电信北楼320判断某年是否为闰年二、实验内容1、判断某年月是否为闰年；2、判断某年月有多少天；3、有if~else结构对五个数排序；4、求100~1000内的所有非素数。

三、实验步骤、源程序及实验结果1、判断某年月是否为闰年源程序：import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;public class LeapYear {public static void main(String[] args) throws NumberFormatException, IOException {int year;InputStreamReader reader=new InputStreamReader(System.in);BufferedReader input=new BufferedReader(reader);System.out.println("请输入年份：");year=Integer.parseInt(input.readLine());if((year%4==0)&&(year%100==0)||(year%400==0))System.out.println("是闰年！");elseSystem.out.println("不是闰年！");}}运行结果：2、判断某年月有多少天源程序：import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;public class MonthDays {int year;public void setyear(int year){this.year=year;}public boolean boolyear(){boolean b=true;if((year%4==0)&&(year%100==0)||(year%400==0))b=true;elseb=false;return b;}public static void main(String[] args) throws NumberFormatException, IOException {MonthDays md=new MonthDays();int year,month,days;InputStreamReader reader=new InputStreamReader(System.in);BufferedReader input=new BufferedReader(reader);System.out.println("请输入年份：");year=Integer.parseInt(input.readLine());System.out.println("请输入月份：");month=Integer.parseInt(input.readLine());md.setyear(year);boolean b=md.boolyear();switch(month){case 1:case 3:case 5:case 7:case 8:case 10:case 12:days=31;System.out.println("本月是"+days+"天");System.out.println("本年是365天");break;case 4:case 6:case 9:case 11:days=30;System.out.println("本月是"+days+"天");System.out.println("本年是365天");case 2:if(b==true){days=29;System.out.println("本月是"+days+"天");System.out.println("本年是366天");}else{days=28;System.out.println("本月是"+days+"天");System.out.println("本年是365天");}}}}运行结果：3、有if~else结构对五个数排序源程序：import java.util.Random;public class paixu {public static void main(String[] args) {Random random =new Random();float a=random.nextFloat();System.out.println("a="+a);float b=random.nextFloat();System.out.println("b="+b);float c=random.nextFloat();System.out.println("c="+c);float d=random.nextFloat();System.out.println("d="+d);float e=random.nextFloat();System.out.println("e="+e);if(a<b)if(b<c)if(c<d) //System.out.println("abcd");if(d<e) System.out.println("a<b<c<d<e");elseif(c<e) System.out.println("a<b<c<e<d");elseif(b<e) System.out.println("a<b<e<c<d");elseif(a<e) System.out.println("a<e<b<c<d");else System.out.println("e<a<b<c<d");elseif(b<d) //System.out.println("abdc");if(c<e) System.out.println("a<b<d<c<e");elseif(d<e) System.out.println("a<b<d<e<c");elseif(b<e) System.out.println("a<b<e<d<c");elseif(a<e)System.out.println("a<e<b<d<c");else System.out.println("e<a<b<d<c");elseif(a<d) //System.out.println("adbc");if(c<e) System.out.println("a<d<b<c<e");elseif(b<e) System.out.println("a<d<b<e<c");elseif(d<e)System.out.println("a<d<e<b<c");elseif(a<e)System.out.println("a<e<d<b<c");elseSystem.out.println("e<a<d<b<c");else//System.out.println("dabc");if(c<e) System.out.println("d<a<b<c<e");elseif(b<e) System.out.println("d<a<b<e<c");elseif(a<e)System.out.println("d<a<e<b<c");elseif(d<e)System.out.println("d<e<a<b<c");elseSystem.out.println("e<d<a<b<c");elseif(a<c)//System.out.println("a<c<b");//acbif(b<d) //System.out.println("acbd");if(d<e) System.out.println("a<c<b<d<e");elseif(b<e) System.out.println("a<c<b<e<d");elseif(c<e) System.out.println("a<c<e<b<d");elseif(a<e)System.out.println("a<e<c<b<d");else System.out.println("e<a<c<b<d");elseif(c<d) //System.out.println("acdb");if(b<e) System.out.println("a<c<d<b<e");elseif(d<e) System.out.println("a<c<d<e<b");elseif(c<e)System.out.println("a<c<e<d<b");elseif(a<e)System.out.println("a<e<c<d<b");elseSystem.out.println("e<a<c<d<b");elseif(a<d) //System.out.println("adcb");if(b<e) System.out.println("a<d<c<b<e");elseif(c<e)System.out.println("a<d<c<e<b");elseif(d<e)System.out.println("a<d<e<c<b");elseif(a<e)System.out.println("a<e<d<c<b");elseSystem.out.println("e<a<d<c<b");else//System.out.println("dacb");if(b<e) System.out.println("d<a<c<b<e");elseif(c<e)System.out.println("d<a<c<e<b");elseif(a<e)System.out.println("d<a<e<c<b");elseif(d<e)System.out.println("d<e<a<c<b");elseSystem.out.println("e<d<a<c<b");else//System.out.println("cab");//cabif(b<d) //System.out.println("cabd");if(d<e) System.out.println("c<a<b<d<e");elseif(b<e) System.out.println("c<a<b<e<d");elseif(a<e) System.out.println("c<a<e<b<d");elseif(c<e)System.out.println("c<e<a<b<d");else System.out.println("e<c<a<b<d");elseif(a<d) //System.out.println("cadb");if(b<e) System.out.println("c<a<d<b<e");elseif(d<e) System.out.println("c<a<d<e<b");elseif(a<e)System.out.println("c<a<e<d<b");elseif(c<e)System.out.println("c<e<a<d<b");elseSystem.out.println("e<c<a<d<b");elseif(c<d) //System.out.println("cdab");if(b<e) System.out.println("c<d<a<b<e");elseif(a<e)System.out.println("c<d<a<e<b");elseif(d<e)System.out.println("c<d<e<a<b");elseif(c<e)System.out.println("c<e<d<a<b");elseSystem.out.println("e<c<d<a<b");else//System.out.println("dcab");if(b<e) System.out.println("d<c<a<b<e");elseif(a<e)System.out.println("d<c<a<e<b");elseif(c<e)System.out.println("d<c<e<a<b");elseif(d<e)System.out.println("d<e<c<a<b");elseSystem.out.println("e<d<c<a<b");elseif(a<c) //System.out.println("bac");//if(c<d) //System.out.println("bacd");if(d<e) System.out.println("b<a<c<d<e");elseif(c<e) System.out.println("b<a<c<e<d");elseif(a<e) System.out.println("b<a<e<c<d");elseif(b<e) System.out.println("b<e<a<c<d");else System.out.println("e<b<a<c<d");elseif(a<d) //System.out.println("badc");if(c<e) System.out.println("b<a<d<c<e");elseif(d<e) System.out.println("b<a<d<e<c");elseif(a<e) System.out.println("b<a<e<d<c");elseif(b<e)System.out.println("b<e<a<d<c");else System.out.println("e<b<a<d<c");elseif(b<d) //System.out.println("bdac");if(c<e) System.out.println("b<d<a<c<e");elseif(a<e) System.out.println("b<d<a<e<c");elseif(d<e)System.out.println("b<d<e<a<c");elseif(b<e)System.out.println("b<e<d<a<c");elseSystem.out.println("e<b<d<a<c");else//System.out.println("dbac");if(c<e) System.out.println("d<b<a<c<e");elseif(a<e) System.out.println("d<b<a<e<c");elseif(d<e)System.out.println("d<b<e<a<c");elseif(b<e)System.out.println("d<e<b<a<c");elseSystem.out.println("e<d<b<a<c");elseif(b<c) //System.out.println("bca");if(a<d) //System.out.println("bcad");if(d<e) System.out.println("b<c<a<d<e");elseif(a<e) System.out.println("b<c<a<e<d");elseif(c<e) System.out.println("b<c<e<a<d");elseif(b<e)System.out.println("b<e<c<a<d");else System.out.println("e<b<c<a<d");elseif(c<d) //System.out.println("bcda");if(a<e) System.out.println("b<c<d<a<e");elseif(b<e) System.out.println("b<c<d<e<a");elseif(c<e)System.out.println("b<c<e<d<a");elseif(d<e)System.out.println("b<e<c<d<a");elseSystem.out.println("e<b<c<d<a");elseif(b<d) //System.out.println("bdca");if(a<e) System.out.println("b<d<c<a<e");elseif(c<e)System.out.println("b<d<c<e<a");elseif(d<e)System.out.println("b<d<e<c<a");elseif(b<e)System.out.println("b<e<d<c<a");elseSystem.out.println("e<b<d<c<a");else//System.out.println("dbca");if(a<e) System.out.println("d<b<c<a<e");elseif(c<e)System.out.println("d<b<c<e<a");elseif(b<e)System.out.println("d<b<e<c<a");elseif(d<e)System.out.println("d<e<b<c<a");elseSystem.out.println("e<d<b<c<a");else//System.out.println("cba");if(a<d) //System.out.println("cbad");if(d<e) System.out.println("c<b<a<d<e");elseif(a<e) System.out.println("c<b<a<e<d");elseif(b<e) System.out.println("c<b<e<a<d");elseif(c<e)System.out.println("c<e<b<a<d");else System.out.println("e<c<b<a<d");elseif(b<d) //System.out.println("cbda");if(a<e) System.out.println("c<b<d<a<e");elseif(d<e) System.out.println("c<b<d<e<a");elseif(b<e)System.out.println("c<b<e<d<a");elseif(c<e)System.out.println("c<e<b<d<a");elseSystem.out.println("e<c<b<d<a");elseif(c<d) //System.out.println("cdba");if(a<e) System.out.println("c<d<b<a<e");elseif(b<e)System.out.println("c<d<b<e<a");elseif(d<e)System.out.println("c<d<e<b<a");elseif(c<e)System.out.println("c<e<d<b<a");elseSystem.out.println("e<c<d<b<a");else//System.out.println("dcba");if(a<e) System.out.println("d<c<b<a<e");elseif(b<e)System.out.println("d<c<b<e<a");elseif(c<e)System.out.println("d<c<e<b<a");elseif(d<e)System.out.println("d<e<c<b<a");elseSystem.out.println("e<d<c<b<a");}}运行结果：4、求100~1000内的所有非素数源程序：public class PrimeNumber {public static void main(String[] args) {System.out.println("***prime numbers between 100 and 1000***");int n=0,i=0,j;for(i=100;i<=1000;i++)for(j=2;j<=Math.sqrt(i);j++){if(i%j==0){if(n<22){System.out.print(" "+i);n++;break;}else {System.out.println(" "+i);n=0;}}}}}运行结果：本人在做第四小题时，程序的运行结果如下图（截了部分图），并没有出现正确的结果。