# JSDevLife

You will find javascript program and solution at single place.

## Saturday, 2 July 2022

Hello friends,
If you come here to check the solution of the following question.

# JavaScript find valid palindrome or not

## this question is asked in LeetCode as a valid palindrome(Question Number -125) and its difficulty is easy.

If you search on google mostly we get solutions in Java, Python, or C++. if we are lucky then only we get the solution in javascript for the leet code questions.

So let's first understand the question.

A phrase is a palindrome if it reads the same forward and backward after converting all uppercase letters into lowercase letters and removing all non-alphanumeric characters. Alphanumeric characters include letters and numbers.

Given a string `s`, return `true` if it is a palindrome, or `false` otherwise.

Example 1:

```Input: s = "A man, a plan, a canal: Panama"
Output: true
Explanation: "amanaplanacanalpanama" is a palindrome.
```

Example 2:

```Input: s = "race a car"
Output: false
Explanation: "raceacar" is not a palindrome.
```

Example 3:

```Input: s = " "
Output: true
Explanation: s is an empty string "" after removing non-alphanumeric characters.
Since an empty string reads the same forward and backward, it is a palindrome.
```

Constraints:

• ```1 <= s.length <= 2 * 105```
• `s` consists only of printable ASCII characters.

So the solution to the above question is.

``````

/**
* @param {string} s
* @return {boolean}
*/
var isPalindrome = function(s) {

s = s.toLowerCase().replace(/[\W_]/g,""); 	// replace() method will replace all non alphanumeric to empty chars
let left = 0;
let right = s.length-1;
while(left < right){
if(s[left]!==s[right]){
return false;
}
left++;
right--;

}
return true;

};
```

```

Complexity of the solution is as follows:

Time Complexity: O(N)

Space Complexity: O(1)