added utf-16-base64 example

README.md

@@ -26,7 +26,8 @@ It also consolidates all relevant examples in 1 place
 │       ├── async.js
 │       ├── image.png
 │       └── README.md
-
+│   └── encoding
+│       └── utf-16-base64.js # an example showing how to encode/decode UTF-16 strings
 ├── js-ts-frameworks # JS-TS framework specific examples
 │   ├── Angular
 │   │   └── state

javascript/encoding/utf-16-base64.js

@@ -0,0 +1,41 @@
+/**
+ * Base 64 encodes UTF-16 encoded strings
+ *
+ * @param {*} string
+ * @return {*}
+ */
+function btoaUTF16(string) {
+  const charCodeArray = new Uint16Array(string.length);
+
+  // you could use a for loop without the split to move in the string for better performance
+  string.split("").forEach((_, index) => {
+    charCodeArray[index] = string.charCodeAt(index);
+  });
+
+  return btoa(String.fromCharCode(...new Uint16Array(charCodeArray.buffer)));
+}
+
+/**
+ * Decodes base64 encoded UTF-16 strings
+ *
+ * @param {*} encoded
+ * @return {*}
+ */
+function atobUTF16(encoded) {
+  binary = atob(encoded);
+  const bytes = new Uint16Array(binary.length);
+
+  // you could use a for loop without the split to move in the string for better performance
+  binary.split("").forEach((_, index) => {
+    bytes[index] = binary.charCodeAt(index);
+  });
+
+  return String.fromCharCode(...new Uint16Array(bytes.buffer));
+}
+
+// Our base64 string with weird chars
+const encoded = btoaUTF16("HUË - Sársziget");
+const decoded = atobUTF16(encoded);
+
+console.log("encoded:", encoded);
+console.log("decoded:", decoded);