Java Program to Check if a Given String is Palindrome
This is java basic program which asked by interviewer to Write a Java program that accepts a string and checks whether a given string is a palindrome or not.
Before you write the code let’s understand that
What is String Palindrome Program in Java?
A palindrome is a word, phrase, or sentence that reads the same backward or forward. A string is said to be a palindromic string when we traverse it from start to end or end to start then we get the same result.
Examples:
ada, malayalam, racecar, mom, etc.
Example 1:
Input: String = “RACECAR”
Output: racecar is a Palindrome
Explanation: The reverse of the given string is equal to the (RACECAR) is equal to the given string. Therefore, the given string is a palindromic string.
Example 2:
Input: String = “SUNDAY”
Output: SUNDAY is not a Palindrome
Explanation: The reverse of the given string is equal to the (YADNUS) which is not equal to the given string. Therefore, the given string is not a palindromic string.
Example 3:
Input: String = “RADAR”
Output: RADAR is a Palindrome
Explanation: The reverse of the given string is equal to the (RADAR) which is equal to the given string. Therefore, the given string is a palindromic string.

Problem Solution:
1. Take a string as input.
2. Reverse the string.
3. If they are equal, print the string is a Palindrome else print, the string is not a palindrome.
Find the Palindrome using user input for loop in java
/*
* Author: Zameer Ali
* */
import java.util.Scanner;
public class Palindrome
{
public static void main(String args[])
{
String a, b = "";
Scanner s = new Scanner(System.in);
System.out.print("Enter a string:");
a = s.nextLine();
int n = a.length();
for(int i = n - 1; i >= 0; i--)
{
b = b + a.charAt(i);
}
if(a.equalsIgnoreCase(b))
{
System.out.println(a+ " is a palindrome.");
}
else
{
System.out.println(a+ " is not a palindrome.");
}
}
}
Output:
Enter a string: sunday
sunday is not a palindrome
Find the Palindrome using for loop in java
/*
* Author: Zameer Ali
* */
public class StringIsAPalindromeOrNot {
public static void main(String[] args) {
String s = "arora";
String rev = "";
for (int i = s.length()-1; i >=0 ; i--)
rev=rev+s.charAt(i);
if(s.equals(rev))
System.out.println("String is palindrome");
else
System.out.println("String is not palindrome");
}
}
Output:
String is palindrome
Java Program to Check Palindrome Number
/*
* Author: Zameer Ali
* */
class Main {
public static void main(String[] args) {
int num = 3553, reversedNum = 0, remainder;
// store the number to originalNum
int originalNum = num;
// get the reverse of originalNum
// store it in variable
while (num != 0) {
remainder = num % 10;
reversedNum = reversedNum * 10 + remainder;
num /= 10;
}
// check if reversedNum and originalNum are equal
if (originalNum == reversedNum) {
System.out.println(originalNum + " is Palindrome.");
}
else {
System.out.println(originalNum + " is not Palindrome.");
}
}
}
Output:
3553 is Palindrome.