无法找出Java程序检查字符串是否为回文的解决方案

Question

I wrote the java code to find out whether the string is a palindrome or not. But, I am not getting the required result. Please suggest necessary change in code.

public class Test1 
{
        public static void main(String[] args)
        {
            String original="madam";
            String rev="";
            int len=original.length();
            System.out.println(len);
            boolean flag=false;
            for(int i=len-1,j=1;i>0;i--,j++)
            {
                if(original.charAt(i)==original.charAt(j))
                        {
                         flag=true;
                         continue;
                        }
                else
                {
                    flag=false;
                    break;
                }
            }

            if(flag)
                System.out.println("palindrome");
            else
                System.out.println("not a polindrom");
        }   
}

Answer 1

Try this:

public class Test1 
{
        public static void main(String[] args)
        {
            String original="madam";

            int len=original.length();
            System.out.println(len);

            boolean flag=true;

            for(int i=len-1,j=0;i != j;i--,j++)
            {
                if(original.charAt(i) != original.charAt(j))
                        {
                         flag=false;
                         break;
                        }

            }

            if(flag)
                System.out.println("palindrome");
            else
                System.out.println("not a polindrom");
        }   
}

Answer 2

This will work for you.

It uses the reverse() method of class java.lang.StringBuilder

public class Test1 {

    public static void main(String[] args) {
        String original = "madam";
        StringBuilder sb = new StringBuilder(original);
        String reverse = sb.reverse().toString();
        if (original.equals(reverse)) {
            System.out.println("PALINDROME");
        } else {
            System.out.println("NOT A PALINDROME");
        }
    }
}

Answer 3

Strings are zero-indexed in Java. This means that your j variable is starting at the second character in the string.

Try changing the for loop header to this:

for(int i=len-1,j=0;i>j;i--,j++)