Java Program to Check if a Given String is Palindrome

Write a Java program that accepts a string and checks whether a given string is a palindrome or not.

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.

Let us take a few more examples to understand the problem.

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 = “SANFOUNDRY”
Output: SANFOUNDRY is not a Palindrome
Explanation: The reverse of the given string is equal to the (YRDNUOFNAS) which is not equal to the given string. Therefore, the given string is not a palindromic string.

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.

Here is the source code of the Java Program to Check whether a String is a Palindrome. The Java program is successfully compiled and run on a Windows system. The program output is also shown below.

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.");
        }
    }
}

1. Take a string as input and store it in the array.
2. Use for loops and if-else conditions along with equalsIgnoreCase() method to conclude whether the entered string is palindrome or not.

Testcase 1: In this case, we enter the string “sanfoundry” as input to check whether it is a palindrome string or not.

Enter a string: sanfoundry
sanfoundry is not a palindrome

Testcase 2: In this case, we enter the string “racecar” as input to check whether it is a palindrome string or not.

Enter a string: racecar
racecar is a palindrome

To practice programs on every topic in Java, please visit “Programming Examples in Java”, “Data Structures in Java” and “Algorithms in Java”.