merge second edition

Author: loiane

README.md

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+Learning JavaScript Data Structures and Algorithms
+====================================
+
+Source code of **Learning JavaScript Data Structures and Algorithms** book.
+
+| 1st edition   | 2nd edition   | 
+| ------------- |:-------------:| 
+| ![1st edition](https://d1ldz4te4covpm.cloudfront.net/sites/default/files/imagecache/ppv4_main_book_cover/4874OS_Learning%20JavaScript%20Data%20Structures%20and%20Algorithms.jpg)      | ![2nd edition](https://d255esdrn735hr.cloudfront.net/sites/default/files/imagecache/ppv4_main_book_cover/5493OS_5348_Learning%20JavaScript%20Data%20Structures%20and%20Algorithms,%20Second%20Edition.jpg) | 
+| [Book link](http://amzn.to/1Y1OWPx)| [Book link](http://amzn.to/1TSkcA1)|
+
+Book link - first edition:
+  - [Packt](https://www.packtpub.com/application-development/learning-javascript-data-structures-and-algorithms)
+  - [Amazon](http://amzn.to/1Y1OWPx)
+  - [Chinese version](http://www.ituring.com.cn/book/1613)
+  - [Korean version](http://www.acornpub.co.kr/book/javascript-data-structure)
+
+Book link - second edition:
+ - [Packt](https://www.packtpub.com/web-development/learning-javascript-data-structures-and-algorithms-second-edition)
+ - [Amazon](http://amzn.to/1TSkcA1)
+ - [Brazilian Portuguese version](https://novatec.com.br/livros/estruturas-de-dados-algoritmos-em-javascript/)
+
+### List of Chapters:
+  
+* 01: [JavaScript: a quick overview](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter01)
+* 02: [Arrays](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter02)
+* 03: [Stacks](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter03)
+* 04: [Queues](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter04)
+* 05: [Linked Lists](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter05)
+* 06: [Sets](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter06)
+* 07: [Dictionaries and Hashes](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter07)
+* 08: [Trees](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter08)
+* 09: [Graphs](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter09)
+* 10: [Sorting and searching algorithms](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter10)
+* 11: [Pattern of algorithms](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter11)
+* 12: [Algorithm Complexity](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter12)
+
+### First Edition source code:
+
+Please refer to [this link](https://github.com/loiane/javascript-datastructures-algorithms/tree/master)
+
+### Found an issue or have a question?
+
+Please create an [Issue](https://github.com/loiane/javascript-datastructures-algorithms/issues) or [Pull Request](https://github.com/loiane/javascript-datastructures-algorithms/pulls) 

chapter01/02-Variables.js

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+var num = 1; //{1}
+num = 3; //{2}
+
+var price = 1.5; //{3}
+var name = 'Packt'; //{4}
+var trueValue = true; //{5}
+var nullVar = null; //{6}
+var und;  //7
+
+console.log("num: "+ num);
+console.log("name: "+ name);
+console.log("trueValue: "+ trueValue);
+console.log("price: "+ price);
+console.log("nullVar: "+ nullVar);
+console.log("und: "+ und);
+
+//******* Variable Scope
+
+var myVariable = 'global';
+myOtherVariable = 'global';
+
+function myFunction(){
+    var myVariable = 'local';
+    return myVariable;
+}
+
+function myOtherFunction(){
+    myOtherVariable = 'local';
+    return myOtherVariable;
+}
+
+console.log(myVariable);   //{1}
+console.log(myFunction()); //{2}
+
+console.log(myOtherVariable);   //{3}
+console.log(myOtherFunction()); //{4}
+console.log(myOtherVariable);   //{5}