palindrome code in java code example

Example 1: generate palindrome java

//This function generates a palindrom by recursively reversing a String,
//recursively add it and checks if it's a palindrom

public static String generatePalindrom(String s) {
	return s.equals(reverseString(s)) ? s
				: generatePalindrom(String.valueOf(Integer.parseInt(s) + Integer.parseInt(reverseString(s))));
}

public static String reverseString(String s) {
	return s.length() == 1 ? s : s.charAt(s.length() - 1) + reverseString(s.substring(0, s.length() - 1));
}

Example 2: easy palindrome program in java

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.");   
   }  
}

Example 3: palindrome function java

package test
//The function below checks if a string is a palindrome
//True = Is a palindrome & False = Not a palindrome
	public boolean isPalindromString(String text){
    	String reverse = reverse(text);
      	if(text.equals(reverse))
    	{
        	return true;
      	}
      
      	return false;
    }
//This function returns the reverse String of its input.
//Ex. if given "hello", it will return "olleh"
	public String reverse(String input)
    {     
		if(input == null || input.isEmpty())
        {
			return input;
        }
        	return input.charAt(input.length()- 1) + reverse(input.substring(0, input.length() - 1));
    }

Example 4: palindrome in java

package test
//The function below checks if a string is a palindrome
//True = Is a palindrome & False = Not a palindrome
	public boolean isPalindromString(String text){
    	String reverse = reverse(text);
      	if(text.equals(reverse))
    	{
        	return true;
      	}
      
      	return false;
    }
//This function returns the reverse String of its input.
//Ex. if given "hello", it will return "olleh"
	public String reverse(String input)
    {     
		if(input == null || input.isEmpty())
        {
			return input;
        }
return input.charAt(input.length()- 1) + reverse
                         (input.substring(0, input.length() - 1));
    }

Example 5: java program to find plaindrome

public class Palindrome {

    public static void main(String[] args) {

        int num = 121, reversedInteger = 0, remainder, originalInteger;

        originalInteger = num;

        // reversed integer is stored in variable 
        while( num != 0 )
        {
            remainder = num % 10;
            reversedInteger = reversedInteger * 10 + remainder;
            num  /= 10;
        }

        // palindrome if orignalInteger and reversedInteger are equal
        if (originalInteger == reversedInteger)
            System.out.println(originalInteger + " is a palindrome.");
        else
            System.out.println(originalInteger + " is not a palindrome.");
    }
}