解法一:
/* * 输入一个5位数,判断它是不是回文数。即12321是回文数,个位与万位相同,十位与千位相同。 * */ public class Test5_22 { public static void main(String[] args) { Boolean boolean1 = Test5_22.isPalindromicNum(12321); System.out.println(boolean1); } //判断是否为回文数 static Boolean isPalindromicNum(int num) { Boolean flag = false; if(num < 10000||num > 100000) { System.out.println("输入格式错误!!!"); return flag; }else { String string = String.valueOf(num); char[] arr = string.toCharArray(); int length = arr.length; for(int i = 0 ; i < length; i ++ ) { if(arr[i] == arr[length -1 - i]) { flag = true; }else { return flag; } } } return flag; } }
解法二:
/* * 判断五位数是否为回文数我们可以将原来的数字进行翻转,比较翻转后数字是否和原数字相同 * */ public class Test5_22{ public static void main(String[] args) { //从控制台输入 Scanner scanner = new Scanner(System.in); System.out.println("请输入五位数字:"); int num = scanner.nextInt(); if(num < 10000 || num > 100000) { System.out.println("输入数字不合法!!!"); }else { //把数字转化成字符串 String string = String.valueOf(num); StringBuilder stringBuilder = new StringBuilder(string); int num1 = Integer.valueOf(stringBuilder.reverse().toString()); if(num == num1) { System.out.println("这个数字是回文数"); }else { System.out.println("这个数字不是回文数"); } } } }