JavaScript/String/AlphaNumericPalindrome.js at master · TheAlgorithms/JavaScript · GitHub

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/**

* @function alphaNumericPalindrome

* @description alphaNumericPalindrome should return true if the string has alphanumeric characters that are palindrome irrespective of special characters and the letter case.

* @param {string} str the string to check

* @returns {boolean}

* @see [Palindrome](https://en.wikipedia.org/wiki/Palindrome)

* @example

* The function alphaNumericPalindrome() receives a string with varying formats

* like "racecar", "RaceCar", and "race CAR"

* The string can also have special characters

* like "2A3*3a2", "2A3 3a2", and "2_A3*3#A2"

* But the catch is, we have to check only if the alphanumeric characters

* are palindrome i.e remove spaces, symbols, punctuation etc

* and the case of the characters doesn't matter

const alphaNumericPalindrome = (str) => {

if (typeof str !== 'string') {

throw new TypeError('Argument should be string')

}

// removing all the special characters and turning everything to lowercase

const newStr = str.replace(/[^a-z0-9]+/gi, '').toLowerCase()

const midIndex = newStr.length >> 1 // x >> y = floor(x / 2^y)

for (let i = 0; i < midIndex; i++) {

if (newStr.at(i) !== newStr.at(~i)) {

// ~n = -(n + 1)

return false

}

return true

}

JavaScript/String/AlphaNumericPalindrome.js at master · TheAlgorithms/JavaScript · GitHub

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JavaScript/String/AlphaNumericPalindrome.js at master · TheAlgorithms/JavaScript · GitHub

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