Problem 3 (10 points) Create a class named Palindrome.java then implements the r

Question

Problem 3 (10 points)

Create a class named Palindrome.java then implements the recursive method specified below:
public boolean isPalindrome(String s)
The recursive method: isPalindrome takes a string as a parameter and that returns true if the string is a palindrome and false if it is not. A palindrome is a string like "racecar" that has the same sequence of characters when written forwards and backwards. Notice that in a palindrome, the first and last characters match, as do the second and second-to-last, the third and third-to-last, and so on. However, when we test if a string is a palindrome, we only consider alphabetic letters(a-z and ignore cases) and digits (0-9), we simply ignore all other symbols. The table below includes various method calls and the value returned:
Method Call Result ------------------------------------------------------------- isPalindrome("radar") true isPalindrome("Was It A Rat I Saw?") true isPalindrome("pe e p") true isPalindrome("x") true isPalindrome("12321") true    isPalindrome("Java") false



Problem 3 (10 points)

Create a class named Palindrome.java then implements the recursive method specified below:
public boolean isPalindrome(String s)
The recursive method: isPalindrome takes a string as a parameter and that returns true if the string is a palindrome and false if it is not. A palindrome is a string like "racecar" that has the same sequence of characters when written forwards and backwards. Notice that in a palindrome, the first and last characters match, as do the second and second-to-last, the third and third-to-last, and so on. However, when we test if a string is a palindrome, we only consider alphabetic letters(a-z and ignore cases) and digits (0-9), we simply ignore all other symbols. The table below includes various method calls and the value returned:
Method Call Result ------------------------------------------------------------- isPalindrome("radar") true isPalindrome("Was It A Rat I Saw?") true isPalindrome("pe e p") true isPalindrome("x") true isPalindrome("12321") true    isPalindrome("Java") false



were 10 failures:

Explanation / Answer

-------------------------------------------------------Palindrome.java-----------------------------------------------------------

import java.util.Scanner;

public class Palindrome {

//This is boolean method for checking palindrome of String .

public static boolean isPalindrome(String str)

{

/*

* first change the string to lower case than removing all the characters of String except

* character 'a' to 'z' and digits 0 to 9.

*/

String s=str.toLowerCase().replaceAll("[^a-z0-9]", ""); //

StringBuilder sb=new StringBuilder(s);//saving String to SrtingBuilder because String Builder id mutable

sb.reverse();//reverse the String using reverse() method of String Builder class.

String rev=sb.toString(); //again saving String builder to String Class.

//checking if reverse string and given string if true then return true else false

if(rev.equals(s))

return true;

else

return false;

}

//main method

public static void main(String[] args) {

//for your given input

System.out.println("isPalindrome("radar") : "+isPalindrome("radar"));

System.out.println("isPalindrome("pe e p") : "+isPalindrome("pe e p"));

System.out.println("isPalindrome("Was It A Rat I Saw?") : "+isPalindrome("Was It A Rat I Saw?"));

System.out.println("isPalindrome("12321") : "+isPalindrome("12321"));

System.out.println("isPalindrome("java") :"+isPalindrome("java"));

//to getting String from user

System.out.println("Enter the String : ");

Scanner sc=new Scanner(System.in);

String str=sc.nextLine();

System.out.println("isPalindrome(""+str+"") : "+isPalindrome(str));

sc.close();

}

}

-----------------------------------------------------------Output---------------------------------------------------------------------

isPalindrome("radar") : true
isPalindrome("pe e p") : true
isPalindrome("Was It A Rat I Saw?") : true
isPalindrome("12321") : true
isPalindrome("java") :false
Enter the String :
javaj
isPalindrome("javaj") : true

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