# How to Check If a String Is Palindrome or Not Using Various Python Programs?

### Introduction

A palindrome is a word, phrase, number, or another sequence of units that will read the same way in either direction; generally, if used, commas, separators or other word dividers are ignored. Punctuation and spaces between the words or lettering are allowed. Examples of palindromes include “A man, a plan, a canal, Panama!”, “Was it a car or a cat I saw?”, “No ‘x’ in Nixon”, “radar”, “racecar”, “redder”, “Refer”, “refer”, “level”, “madam”, and “nurses run”.

### What Is Palindrome Number In Python?

A palindrome is a number that is the same when reversed. For example, 121 is a palindrome because it is the same when reversed. Python has a built-in function called str that can be used to reverse a string, and we can use this function to check if a number is a palindrome.

Method To Check If A String Is a Palindrome

Given below are the methods you can use to check whether a string is a palindrome or not.

Method 1: Using the == Operator

One of the most simple ways to check if a string is a palindrome or not is by using the == operator. This comparison operator compares the two operands on either side of it and returns True if they are the same and False otherwise.

We can use this to our advantage to check if a string is a palindrome or not. All we need to do is reverse the string and compare it with the original string. If both strings are equal, then the string is a palindrome.

Method 2: Using the reversed() Function

Python has a built-in function called reversed() which returns a reversed iterator object. We can use this function to create a new string that is the original string’s reverse. Then, we can simply compare both strings to check if the string is a palindrome or not.

Method 3: Using the reduce() Function

The reduce() function is widely used in functional programming. It applies a function to the first two elements of an iterable and then carries out the same operation on the result of the first function, the third element, and so on.

We can use this function to check if a string is a palindrome or not. All we need to do is pass the string as an argument to the reduce() function along with the lambda function, which checks if the first character is equal to the last character and so on. The string is a palindrome if all the characters satisfy this condition.

Method 4: Using Recursion

Recursion is a process in which a function calls itself. We can use recursion to check if a string is a palindrome or not.

All we need to do is pass the string to a recursive function that compares the first character with the last character, then the second character with the second last character, and so on. If all the characters match, then the string is a palindrome.

Method 5: Using For Loop To Check If A String Is a Palindrome

A string is a palindrome if it reads the same when it is either read forward or backward. For example, the string “abcba” is a palindrome, while the string “abcd” is not.

To check if a string is a palindrome using a for loop, we can use the following steps:

1. Initialize a variable “left” to point to the first character in the string.
2. Initialize a variable “right” to point to the last character in the string.
3. While “left” is less than or equal to “right”, compare the characters at the “left” and “right” indices. If they are not the same, then the string is not a palindrome, and we can return false.
4. If we reach the end of the loop without returning false, then we know that the string is a palindrome, and we can return true.

Method 6: Using Reversed Function To Check If A String Is a Palindrome

Another way to check if a string is a palindrome is to use the built-in JavaScript function Array.prototype.reverse(). This function reverses the order of the elements in an array.

We can use this function to reverse a string and then compare it to the original string. If the reversed string is the same as the original string, then the string is a palindrome.

We can use the following steps to check if a string is a palindrome using the reversed function:

1. Use the split() method to split the string into an array of characters.
2. Use the reverse() method to reverse the order of the elements in the array.
3. Use the join() method to join the elements in the array back into a string.
4. Compare the reversed string to the original string. If they are the same, then the string is a palindrome.

Method 7: Using While Loop To Check If A String Is a Palindrome

We will be using a while loop to check if a string is a palindrome. A palindrome is a word or phrase that is the same as forwards and backward. For example, “racecar” is a palindrome.

1. Initialize a variable “left” to point to the first character in the string.
2. Initialize a variable “right” to point to the last character in the string.
3. While “left” is less than or equal to “right,” compare the characters at the “left” and “right” indices. If they are not the same, then the string is not a palindrome, and we can return false.
4. If we reach the end of the loop without returning false, then we know that the string is a palindrome, and we can return true.

If the string is a palindrome, the function will return true. If the string is not a palindrome, the function will return false.

#### Conclusion

The three methods for determining whether or not a string is a palindrome have been covered in this blog. The straightforward method of reversing a string and then testing it has been covered. We have also covered the iterative method and the reversed() function’s application in palindrome checking. Go to the UNext Jigsaw website to study Python strings in-depth. You may enroll in whatever courses you desire and advance your skills in a variety of subjects.

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