diff --git a/arrays_strings/reverse_string/reverse_string_solution.ipynb b/arrays_strings/reverse_string/reverse_string_solution.ipynb
index a3687e7..8ee2e6e 100644
--- a/arrays_strings/reverse_string/reverse_string_solution.ipynb
+++ b/arrays_strings/reverse_string/reverse_string_solution.ipynb
@@ -65,7 +65,7 @@
     "Since Python strings are immutable, we'll use a list of chars instead to exercise in-place string manipulation as you would get with a C string.\n",
     "\n",
     "* Iterate len(string)/2 times, starting with i = 0:\n",
-    "    * Swap i and len(string) - 1 - i\n",
+    "    * Swap char with index (i) and char with index (len(string) - 1 - i)\n",
     "    * Increment i\n",
     "\n",
     "Complexity:\n",
@@ -97,12 +97,11 @@
     "class ReverseString(object):\n",
     "\n",
     "    def reverse(self, chars):\n",
-    "        if chars is None or not chars:\n",
-    "            return chars\n",
-    "        size = len(chars)\n",
-    "        for i in range(size // 2):\n",
-    "            chars[i], chars[size - 1 - i] = \\\n",
-    "                chars[size - 1 - i], chars[i]\n",
+    "        if chars:\n",
+    "            size = len(chars)\n",
+    "            for i in range(size // 2):\n",
+    "                chars[i], chars[size - 1 - i] = \\\n",
+    "                    chars[size - 1 - i], chars[i]\n",
     "        return chars"
    ]
   },
@@ -126,14 +125,14 @@
     "class ReverseStringAlt(object):\n",
     "\n",
     "    def reverse_string_alt(string):\n",
-    "        if string is None or not string:\n",
-    "            return string\n",
-    "        return string[::-1]\n",
+    "        if string:\n",
+    "            return string[::-1]\n",
+    "        return string\n",
     "\n",
     "    def reverse_string_alt2(string):\n",
-    "        if string is None or not string:\n",
-    "            return string\n",
-    "        return ''.join(reversed(string))"
+    "        if string:\n",
+    "            return ''.join(reversed(string))\n",
+    "        return string"
    ]
   },
   {