Palindrome in Java: Palindromes with Advanced Techniques

Are you interested in exploring Palindrome in Java? Let’s delve into the details in this comprehensive guide.

Introduction to Palindrome In Java#

Palindromes, fascinating sequences of characters, have the unique property of reading the same forwards and backwards.

Now, let’s explore some captivating examples of palindrome patterns.

Numeric Palindromes#

Palindrome Words, Sentences, and Names#

1. Palindromic Words

Words like “rotor,” “civic,” “level,” and “racecar.”

2. Palindromic Names

Names such as “anna,” “eve,” and “bob.”

3. Palindromic Sentences

Sentences like “Was it a car or a cat I saw,” “Mr. Owl ate my metal worm,” and “Do geese see god.”

Using Java for Palindrome Validation#

Let’s embark on a journey to create a Java program that can determine whether a given number is a palindrome.

In our example, we’ll use the number 151, declared as an integer variable.

To achieve this, we’ll employ the logic of a for loop for iteration.

Furthermore, we’ll introduce a temporary variable called “actualValue” to store the original string and perform a comparison with its reversed counterpart.

Palindrome Number Validation Using a For Loop#

public static void main(String[] args) {
    try {
        int number = 151; 
        int reverseValue = 0;
        int reminder; 
        int actualValue;
        actualValue = number;
        for(;number!= 0; number /= 10) {
            reminder = number % 10;
            reverseValue = reverseValue * 10 + reminder;
        }
        if (actualValue == reverseValue)
            System.out.println(actualValue + " is a valid palindrome.");
        else
            System.out.println(actualValue + " is not a valid palindrome.");
    } catch (Exception e) {
        e.printStackTrace();
    }
}
Output:
151 is a valid palindrome.

As demonstrated by the above output, the original input number, 151, matches its reversed form, resulting in a valid palindrome.

Now, let’s explore an alternative approach using a while loop in the Java program below.

public static void main(String[] args) {
    try {
        int number = 151; 
        int reverseValue = 0;
        int reminder; 
        int actualValue;
        actualValue = number;
        while (number != 0) {
            reminder = number % 10;
            reverseValue = reverseValue * 10 + reminder;
            number /= 10;
        }
        if (actualValue == reverseValue)
            System.out.println(actualValue + " is a valid palindrome.");
        else
            System.out.println(actualValue + " is not a valid palindrome.");
    } catch (Exception e) {
        e.printStackTrace();
    }
}
Output:
151 is a valid palindrome.

As seen in the above output, the original number matches its reversed form.

In essence, a palindrome reads the same from left to right and right to left, much like our number 151.

You May Also Be Interested In:

• How to Remove a Character from a String in Python
• 4 Ways to Remove Characters from a String in JavaScript

Validating Palindrome Strings#

In this section, we’ll explore the validation of strings as palindromes in Java.

Let’s create a Palindrome program to determine whether an input string is a palindrome or not.

Here’s an example:

public static void main(String[] args) {
    try {
        String inputValue = "rotor"; 
        String reverseValue = "";
        int length = inputValue.length();   
        for (int x = length - 1; x >= 0; x--)  
            reverseValue = reverseValue + inputValue.charAt(x);  
        if (inputValue.equals(reverseValue))
            System.out.println(inputValue + " is a valid palindrome.");
        else
            System.out.println(inputValue + " is not a valid palindrome.");
    } catch (Exception e) {
        e.printStackTrace();
    }
}
Output:
rotor is a valid palindrome.

As demonstrated by the above output, the input character sequence “rotor” matches its reversed form, resulting in a valid palindrome.

Palindrome Validation Using the Reverse Method#

In this section, we’ll explore palindrome validation in Java using the reverse method.

We’ll make use of the `reverse()` method from the Java library’s StringBuffer.

With the following Palindrome program, we’ll check if a given string is a palindrome.

The program will compare the original string with its reversed version and provide the result accordingly.

public static void main(String[] args) {
    try {
        String inputValue ="Ana";
        String reverseValue = new StringBuffer(inputValue).reverse().toString(); 		  
        if (inputValue.equalsIgnoreCase(reverseValue)) 		      
            System.out.println(inputValue + " is a valid palindrome.");		  
        else
            System.out.println(inputValue + " is not a valid palindrome.");
    } catch (Exception e) {
        e.printStackTrace();
    }
}
Output:
Ana is a valid palindrome.

As evident from the output above, the input “Ana” matches its reversed form, resulting in a valid palindrome.

In conclusion, this tutorial has covered various methods for validating palindromes in Java.

Frequently Asked Questions (FAQs)#