程序：使用递归检查String是否为回文
package beginnersbook.com;import java.util.Scanner;class PalindromeCheck{ //My Method to check public static boolean isPal(String s) { // if length is 0 or 1 then String is palindrome if(s.length() == 0 || s.length() == 1) return true; if(s.charAt(0) == s.charAt(s.length()-1)) /* check for first and last char of String: * if they are same then do the same thing for a substring * with first and last char removed. and carry on this * until you string completes or condition fails * Function calling itself: Recursion */ return isPal(s.substring(1, s.length()-1)); /* If program control reaches to this statement it means * the String is not palindrome hence return false. */ return false; } public static void main(String[]args) { //For capturing user input Scanner scanner = new Scanner(System.in); System.out.println("Enter the String for check:"); String string = scanner.nextLine(); /* If function returns true then the string is * palindrome else not */ if(isPal(string)) System.out.println(string + " is a palindrome"); else System.out.println(string + " is not a palindrome"); }}
输出：
Enter the String for check:qqaabbqqaabb is not a palindrome
输出 2：
Enter the String for check:cocoococcocoococ is a palindrome
