使用java檢查字符串是否為回文

Question

import java.util.Scanner;

public class palindrome{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String str = sc.nextLine();
        String rev;
        for(int i=str.length()-1,k=0;i>=0 && k<str.length();i--,k++)
        {
            rev.charAt(k) = str.charAt(i);
        }
        if(rev==str)
        System.out.println("string is palidrome");
        else
        System.out.println("string is not palindrome");
    }
}

這段代碼有什么問題？ 注意：錯誤顯示在以下代碼行 rev.charAt(k)=str.charAt(i);

Answer 1

.charAt(k) 不返回位置，它只告訴您那里是什么字符。

Answer 2

回文程序示例代碼

import java.util.*; 

class PalindromeExample2  
{  
   public static void main(String args[])  
   {  
      String original, reverse = ""; // Objects of String class  
      Scanner in = new Scanner(System.in);   
      System.out.println("Enter a string/number to check if it is a palindrome");  
      original = in.nextLine();   
      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/number is a palindrome.");  
      else  
         System.out.println("Entered string/number isn't a palindrome.");   
   }  
}