First commit.

react/src/StringBuilder.tsx

@@ -0,0 +1,21 @@
+
+
+class StringBuilder 
+{
+    _array: string[] = [];
+
+    append(value: any) {
+        if (typeof(value) === "string")
+        {
+            this._array.push(value);
+        } else {
+            this._array.push(value+"");
+        }
+        return this;
+    }
+    toString(): string {
+        return this._array.join('');
+    }
+}
+
+export default StringBuilder;