Improve code style

Author: tshemsedinov

JavaScript/1-mixed.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const adder = (value) => (x) => value += x;
+const adder = (value) => (x) => (value += x);
 
 const a1 = adder(2);
 

JavaScript/3-mixed.js

@@ -6,7 +6,8 @@ class Adder {
   }
 
   add(x) {
-    return this.value += x;
+    this.value += x;
+    return this.value;
   }
 }