solve valid palindrom [sliding window + chatCodeAt]

Author: JangAyeon

valid-palindrome/JangAyeon.js

@@ -0,0 +1,20 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+var isPalindrome = function (s) {
+  const sLowered = [...s.toLowerCase().replace(" ", "")];
+  const isAlpha = (item) => item.charCodeAt() >= 97 && item.charCodeAt() <= 122;
+  const isNumber = (item) => item.charCodeAt() >= 48 && item.charCodeAt() <= 57;
+  const str = sLowered.filter((c) => isAlpha(c) || isNumber(c));
+  const N = str.length;
+  let [start, end] = [0, N - 1];
+  while (start <= end) {
+    if (str[start] != str[end]) {
+      return false;
+    }
+    start++;
+    end--;
+  }
+  return true;
+};