题目:给一个不多于5位的正整数,要求:一、求它是几位数,二、逆序打印出各位数字。
程序设计:
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import java.util.Scanner; public class Ex24 { public static void main(String[] args) { Ex24 tn = new Ex24(); Scanner s = new Scanner(System.in); long a = s.nextLong(); if (a < 0 || a > 100000 ) { System.out.println( "Error Input, please run this program Again" ); System.exit( 0 ); } if (a >= 0 && a <= 9 ) { System.out.println( a + "是一位数" ); System.out.println( "按逆序输出是" + '\n' + a); } else if (a >= 10 && a <= 99 ) { System.out.println(a + "是二位数" ); System.out.println( "按逆序输出是" ); tn.converse(a); } else if (a >= 100 && a <= 999 ) { System.out.println(a + "是三位数" ); System.out.println( "按逆序输出是" ); tn.converse(a); } else if (a >= 1000 && a <= 9999 ) { System.out.println(a + "是四位数" ); System.out.println( "按逆序输出是" ); tn.converse(a); } else if (a >= 10000 && a <= 99999 ) { System.out.println(a + "是五位数" ); System.out.println( "按逆序输出是" ); tn.converse(a); } } public void converse( long l) { String s = Long.toString(l); char [] ch = s.toCharArray(); for ( int i=ch.length- 1 ; i>= 0 ; i--) { System.out.print(ch[i]); } } } |