js palindrome number

1function palindrome(str) {
2
3    var len = str.length;
4    var mid = Math.floor(len/2);
5
6    for ( var i = 0; i < mid; i++ ) {
7        if (str[i] !== str[len - 1 - i]) {
8            return false;
9        }
10    }
11
12    return true;
13}
14

1const palindrome = (str) => {
2  var text = str.replace(/[.,'!?\- \"]/g, "")
3  return text.search(
4    new RegExp(
5      text
6        .split("")
7        .reverse()
8        .join(""),
9      "i"
10    )
11  ) !== -1;
12}
13  
14//or
15function palindrome(str) {
16  let text = str.replace(/[.,'!?\- \"]/g, "").toUpperCase();
17  for (let i = 0; i > text.length/2; i++) {
18    if (text.charAt(i) !== text.charAt(text.length - 1 - i)) {
19      return false;
20    }
21  }
22  return true;
23}
24console.log(palindrome("Able was I, ere I saw elba.")); //logs 'true'

1const isPalindrome = str => str === str.split('').reverse().join('');
2
3// Examples
4isPalindrome('abc');        // false
5isPalindrom('abcba');       // true

1isPalindrome = function(x) {
2    if (x < 0) {
3        return false;
4    }
5    
6    return x === reversedInteger(x, 0);
7};
8
9reversedInteger = function(x, reversed) {
10    if(x<=0) return reversed;
11        reversed = (reversed * 10) + (x % 10);
12        x = Math.floor(x / 10);
13    
14    return reversedInteger(x, reversed);
15};

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