java program to check palindrome string using recursion

java program to check palindrome string using recursion


Program: Check whether String is palindrome using recursion
package beginnersbook.com;
import java.util.Scanner;
class PalindromeCheck
{
//My Method to check
public static boolean isPal(String s)
{ // if length is 0 or 1 then String is palindrome
if(s.length() == 0 || s.length() == 1)
return true;
if(s.charAt(0) == s.charAt(s.length()-1))
/* check for first and last char of String:
* if they are same then do the same thing for a substring
* with first and last char removed. and carry on this
* until you string completes or condition fails
* Function calling itself: Recursion
*/

return isPal(s.substring(1, s.length()-1));

/* If program control reaches to this statement it means
* the String is not palindrome hence return false.
*/

return false;
}

public static void main(String[]args)
{
//For capturing user input
Scanner scanner = new Scanner(System.in);
System.out.println("Enter the String for check:");
String string = scanner.nextLine();
/* If function returns true then the string is
* palindrome else not
*/

if(isPal(string))
System.out.println(string + " is a palindrome");
else
System.out.println(string + " is not a palindrome");
}
}
Output:
Enter the String for check:
qqaabb
qqaabb
is not a palindrome
Output 2:
Enter the String for check:
cocoococ
cocoococ
is a palindrome

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