Determines whether a string is a palindrome

isPalindrome.js

/**
 * Determines whether a text is a palindrome.
 * Text is lowercased and non-alphabetic characters are removed.
 *
 * @param  {string} text - the words to check
 * @return {boolean}
 */
function isPalindrome(text) {
  if (!text) return false;
  text = text.replace(/[\W_]+/g, '').toLowerCase();
  let l = 0, r = text.length - 1;
  
  while(l < r && text[l++] === text[r--]);
  return l >= r;
}

test.js

isPalindrome(); // false
isPalindrome('Y'); // true
isPalindrome('Ana'); // true

isPalindrome('aaabbb'); // false
isPalindrome('aaoooocc'); // false
isPalindrome('Civic'); // true
isPalindrome('Madam'); // true
isPalindrome('Rotator'); // true

// it removes spaces to compare characters only
isPalindrome('Top spot'); // true
isPalindrome('Step on no pets'); // true
isPalindrome('Anita Lava La Tina'); // true

// it removes non-alphabetic characters in order to compare
isPalindrome('Eva, can I see bees in a cave?'); // true
isPalindrome('Are we not drawn onward to new era?'); // true

How exactly does this return true?

isPalindrome('aaoooocc'); //true

ES6

let isPalindrome = (str) => (str === str.split('').reverse().join('')) ? true : false

// test
console.log(
    isPalindrome('aaabbb'),
    isPalindrome('aaoooocc'),
    isPalindrome('anitalavalatina')
)
// false false true

How exactly does this return true?

isPalindrome('aaoooocc'); //true

ES6

let isPalindrome = (str) => (str === str.split('').reverse().join('')) ? true : false

// test
console.log(
    isPalindrome('aaabbb'),
    isPalindrome('aaoooocc'),
    isPalindrome('anitalavalatina')
)
// false false true

@subversivo58 Yes, it is wrong, I wrote it again from scratch, now it is more concise and shorter :)