java palindrome reverse string code example

Example 1: String palindrome in java without using reverse method

// String palindrome in java without using reverse method
import java.util.Scanner;
public class StringPalindromeDemo 
{
   public static void main(String[] args) 
   {
      Scanner sc = new Scanner(System.in);
      System.out.println("Please enter string to check palindrome: ");
      String strInput = sc.nextLine();
      // converting string to char array
      char[] chString = strInput.toCharArray();       
      // storing reverse string
      String strReverse = "";         
      // reading char by char
      for(int a = chString.length - 1; a >= 0; a--) 
      {
         strReverse = strReverse + chString[a];
      } 
      // printing given string and reversed string
      System.out.println("Given string: " + strInput);
      System.out.println("Reverse String: " + strReverse); 
      // check if given string is palindrome
      if(strInput.equals(strReverse))
      {
         System.out.println("string is palindrome.");
      }
      else
      {
         System.out.println("string is not palindrome.");
      }
   }
}

Example 2: String palindrome in java using array

// String palindrome in java using array
import java.util.Arrays;
import java.util.Scanner;
public class StringPalindromeUsingArray 
{
   public static void main(String[] args) 
   {
      System.out.println("Please enter string to check whether string is palindrome: ");
      Scanner sc = new Scanner(System.in);
      String strInput = sc.nextLine();
      char[] chArray = strInput.toCharArray();
      int size = chArray.length;
      char[] chGiven = Arrays.copyOf(chArray, chArray.length);
      for(int a = 0; a < size / 2; a++) 
      {
         char temp = chArray[a];
         chArray[a] = chArray[size - a - 1];
         chArray[size - a - 1] = temp;
      }
      System.out.println("Given array: " + Arrays.toString(chGiven));
      System.out.println("String palindrome using array: " + Arrays.toString(chArray));
      if(Arrays.equals(chArray, chGiven)) 
      {
         System.out.println("string is palindrome.");
      }
      else 
      {
         System.out.println("string is not a palindrome.");
      }
      sc.close();
   }
}

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