chapter 1: updated code comments

Author: loiane

html/chapter01/03-Operators.js

@@ -1,24 +1,19 @@
 // @ts-check
 
 /* Arithmetic operators */
-var num = 0;
-
+var num = 0; // {1}
 console.log('num value is ' + num);
 
 num = num + 2;
-
 console.log('New num value is ' + num);
 
 num = num * 3;
-
 console.log('New num value is ' + num);
 
 num = num / 2;
-
 console.log('New num value is ' + num);
 
 num++;
-
 num--;
 
 console.log('New num value is ' + num);

html/chapter01/04-TruthyFalsy.js

@@ -22,4 +22,4 @@ testTruthy({}); // true (object is always true)
 var obj = { name: 'John' };
 testTruthy(obj); // true
 testTruthy(obj.name); // true
-testTruthy(obj.age); // age (prop does not exist)
+testTruthy(obj.age); // age (property does not exist)