Reverse a String and Check a Palindrome

Console.WriteLine(Reverse("interview"));                             // weivretni
Console.WriteLine(IsPalindrome("A man, a plan, a canal: Panama"));   // True
Console.WriteLine(IsPalindrome("Hello"));                            // False

// Swaps characters from both ends of a char array. O(n) time, no Array.Reverse or LINQ.
static string Reverse(string text)
{
    char[] chars = text.ToCharArray();
    for (int left = 0, right = chars.Length - 1; left < right; left++, right--)
        (chars[left], chars[right]) = (chars[right], chars[left]);
    return new string(chars);
}

// Two pointers from both ends, skipping punctuation and ignoring case. O(n) time, O(1) extra space.
static bool IsPalindrome(string text)
{
    int left = 0, right = text.Length - 1;
    while (left < right)
    {
        if (!char.IsLetterOrDigit(text[left])) { left++; continue; }
        if (!char.IsLetterOrDigit(text[right])) { right--; continue; }
        if (char.ToLowerInvariant(text[left]) != char.ToLowerInvariant(text[right])) return false;
        left++;
        right--;
    }
    return true;
}