創建迴文的方法

Question

所以我在編程方面很糟糕，我必須爲大學課程做到這一點，並且無法理解我的一些概念。這就是我對此的看法。我究竟做錯了什麼？我如何調用這些方法來將一致的消息返回給main？檢查方法是從另一個網站借來填補空白，同時我試圖找出驗證迴文的字符串緩衝區方法。很多評論都在進行中，尚未完成。如果這太搞砸了，讓我知道，我會重新開始。謝謝。

import java.util.*; 
import java.lang.StringBuffer; 

public class palindrome { 
    public static void main(String[] args) { 

    } 

    public static String retrieveInput(String number) { 
     Scanner input = new Scanner(System.in); 

     System.out.print("Enter a 5 digit integer: "); 
     number = input.toString(); 

     while (number.length() != 5) { 
      System.out.println("ERROR!!! Integer must be 5 digits. Please enter a 5 digit integer: "); 
      System.out.print("Enter a 5 digit integer: "); 
      number = input.toString(); 
     } 
     if (number.matches("[0-9]+")) { 

     } else { 
      System.out.println("ERROR!!! Input must be numeric. Please enter a 5 digit integer: "); 
      System.out.print("Enter a 5 digit integer: "); 
      number = input.toString(); 
     } 
     return number; 
    } 

    // Change, TESTING ONLY!!!!!!! 
    public static String check(String number) { 
     String original = number; 
     String reverse = ""; 

     int length = original.length(); 

     for (int i = length - 1; i >= 0; i--) 
      reverse = reverse + original.charAt(i); 

     if (original.equals(reverse)) 
      System.out.println("Entered string is a palindrome."); 
     else 
      System.out.println("Entered string is not a palindrome."); 

     return number; 
     //StringBuffer Palindrome = new StringBuffer(number); 
     //return number.equals(reverseString); 
    } 

    //StringBuffer original = new StringBuffer(); 
    // StringBuffer reverse = original.reverse(); 
    // if (original != original.reverse()) { 
    // System.out.print("This is not a palindrome"); 
    //} 
    //return number; 

    public static String display(String number) { 
     return number + " is a valid palindrome!"; 
    } 
} 

Answer 1

試一下這個（修改用微小的變化）

import java.util.Scanner; 

public class Palindrome { // Prefer beginning class name with a capital letter 
          // (Java naming convention) 

    public static void main(String[] args) { 

    } 

    public static String retrieveInput(String number) { 
     Scanner input = new Scanner(System.in); 

     System.out.print("Enter a 5 digit integer: "); 
     number = input.nextLine(); // Replace this 

     while (number.length() != 5) { 
      System.out 
        .println("ERROR!!! Integer must be 5 digits. Please enter a 5 digit integer: "); 
      System.out.print("Enter a 5 digit integer: "); 
      number = input.nextLine(); // Replace this 
     } 
     if (number.matches("[0-9]+")) { 

     } else { 
      System.out.println("ERROR!!! Input must be numeric. Please enter a 5 digit integer: "); 
      System.out.print("Enter a 5 digit integer: "); 
      number = input.nextLine(); // Replace this 
     } 

     input.close(); // Close your scanner after you are done using it. 

     return number; 
    } 

    // Change, TESTING ONLY!!!!!!! 
    public static String check(String number) { 
     String original = number; 
     String reverse = ""; 

     int length = original.length(); 

     for (int i = length - 1; i >= 0; i--) 
      reverse = reverse + original.charAt(i); 

     if (original.equals(reverse)) 
      System.out.println("Entered string is a palindrome."); 
     else 
      System.out.println("Entered string is not a palindrome."); 

     return number; 
     // StringBuffer Palindrome = new StringBuffer(number); 
     // return number.equals(reverseString); 
    } 

    // StringBuffer original = new StringBuffer(); 
    // StringBuffer reverse = original.reverse(); 
    // if (original != original.reverse()) { 
    // System.out.print("This is not a palindrome"); 
    // } 
    // return number; 

    public static String display(String number) { 
     return number + " is a valid palindrome!"; 
    } 
}