Palindrome in Java Example

Palindrome:

Logic:
Given Number/String should be equal with the Reversed of the given Number/String.

Eg:
101 – Palindrome Number (Given and Reverse of the given is equal (101 and 101 only)).
100 – Not a Palindrome Number (Given is 100 and Reverse of the given is 001, both are not equal, so its not a palindrome Number).

Level – Palindrome String. (Given and Reverse of the given is equal (Level and leveL)).
Link – Not a Palindrome String. (Given is Link and Reverse of the given is kniL, both are not equal, so its not a palindrome string).

Program to check Palindrome Number:

package com.ngdeveloper;

public class NumberPalindrome {

    public static void main(String[] args) {
        int input = 100;
        checkPalindrome(input);
    }

    private static void checkPalindrome(int Number) {
        int i, j = 0;
        int input = Number;
        int check = input;
        do {
            i = input % 10; // 1
            input = input / 10; // 1
            j = j * 10 + i; // 10+1
        } while (input > 0);
        if (check == j) {
            System.out.println("Palindrome Number");
        } else {
            System.out.println("Not A Palindrome Number");
        }
    }
}

Output:
Input Given: 100

Not A Palindrome Number

Input Given: 101

Palindrome Number

Program to check a Palindrome String:

package com.ngdeveloper;

public class StringPalindrome {

    public static void main(String[] args) {
        String input = "Level";
        checkPalindrome(input);
    }

    private static void checkPalindrome(String input) {
        StringBuffer strBuf = new StringBuffer(input);
        StringBuffer reverse = (StringBuffer) strBuf.reverse();
        if (input.toString().equalsIgnoreCase(reverse.toString())) {
            System.out.println("Palindrome String");
        } else {
            System.out.println("Not A Palindrome String");
        }
    }
}

Output:
Given Input: Level

Palindrome String

Given Input: Link

Not A Palindrome String