JavaScript:实现是否为回文字母数字字符串算法
/**
* @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}
* @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, punct