提供JavaScript版本的《左旋转字符串》

problems/剑指Offer58-II.左旋转字符串.md

@@ -162,7 +162,27 @@ func reverse(b []byte, left, right int){
 }
 ```
 
+JavaScript版本
 
+```javascript
+/**
+ * @param {string} s
+ * @param {number} n
+ * @return {string}
+ */
+var reverseLeftWords = function (s, n) {
+    const reverse = (str, left, right) => {
+        let strArr = str.split("");
+        for (; left < right; left++, right--) {
+            [strArr[left], strArr[right]] = [strArr[right], strArr[left]];
+        }
+        return strArr.join("");
+    }
+    s = reverse(s, 0, n - 1);
+    s = reverse(s, n, s.length - 1);
+    return reverse(s, 0, s.length - 1);
+};
+```