How do I check if a string is a palindrome in JavaScript?
Ava W

To check if a string is a palindrome in JavaScript, you can compare the characters at corresponding positions from the beginning and end of the string. Here's a step-by-step guide on how to achieve this: 1. Get the string you want to check:

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   const string = 'level';

Replace'level' with the string you want to check for palindromicity. 2. Remove non-alphanumeric characters and convert to lowercase (optional): Depending on your requirements, you may want to ignore non-alphanumeric characters and consider the case of the letters. You can use regular expressions and string methods to remove non-alphanumeric characters and convert the string to lowercase.

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   const cleanedString = string.replace(/[^a-zA-Z0-9]/g, '').toLowerCase();

In this example, the regular expression/[^a-zA-Z0-9]/g matches any non-alphanumeric character andreplace() removes them from the string.toLowerCase() converts the string to lowercase. 3. Compare characters at corresponding positions: Use a loop to iterate over the string and compare the characters at corresponding positions from the beginning and end. If at any point the characters do not match, the string is not a palindrome.

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   let isPalindrome = true;
   for (let i = 0, j = cleanedString.length - 1; i < j; i++, j--) {
     if (cleanedString[i] !== cleanedString[j]) {
       isPalindrome = false;
       break;
     }
   }

In this example, afor loop is used with two pointersi andj starting from the beginning and end of the string, respectively. The loop continues untili reachesj. If the characters at positionsi andj do not match, theisPalindrome variable is set tofalse, and the loop is terminated usingbreak. 4. Check the result: After the loop, you can check theisPalindrome variable to determine if the string is a palindrome.

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   if (isPalindrome) {
     console.log('The string is a palindrome.');
   } else {
     console.log('The string is not a palindrome.');
   }

This example simply logs a message indicating whether the string is a palindrome or not. By following these steps, you can check if a string is a palindrome in JavaScript. Remember to consider any necessary string transformations, such as removing non-alphanumeric characters or ignoring case, based on your requirements.

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