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The JavaScript Workshop

You're reading from   The JavaScript Workshop Learn to develop interactive web applications with clean and maintainable JavaScript code

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Product type Paperback
Published in Nov 2019
Publisher Packt
ISBN-13 9781838641917
Length 802 pages
Edition 1st Edition
Languages
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Authors (8):
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Jahred Love Jahred Love
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Jahred Love
Alonzo L. Hosford Alonzo L. Hosford
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Alonzo L. Hosford
Florian Sloot Florian Sloot
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Florian Sloot
Daniel Rosenbaum Daniel Rosenbaum
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Daniel Rosenbaum
Philip Kirkbride Philip Kirkbride
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Philip Kirkbride
Nick Turner Nick Turner
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Nick Turner
Gaurav Mehla Gaurav Mehla
Author Profile Icon Gaurav Mehla
Gaurav Mehla
Joseph Labrecque Joseph Labrecque
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Joseph Labrecque
+4 more Show less
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Toc

Table of Contents (17) Chapters Close

Preface 1. Getting to Know JavaScript 2. Working with JavaScript FREE CHAPTER 3. Programming Fundamentals 4. JavaScript Libraries and Frameworks 5. Beyond the Fundamentals 6. Understanding Core Concepts 7. Popping the Hood 8. Browser APIs 9. Working with Node.js 10. Accessing External Resources 11. Creating Clean and Maintainable Code 12. Using NextGeneration JavaScript 13. JavaScript Programming Paradigms 14. Understanding Functional Programming 15. Asynchronous Tasks Appendix

Data Scope

Data scoping determines the accessibility of variables, functions, and objects in your code during runtime. This means the scope of a variable is controlled by the location of the variable declaration.

In JavaScript, there are two main types of scopes:

  • Global scope
  • Local scope, which includes function level and block level

Global Scope

Every JavaScript application has a global scope in which we can define anything that all the functions in our application can access. All the variables defined outside the functions, blocks, and modules have a global scope. Global variables are available for the lifetime of the application.

Another way of creating global variables is to use predefined global variables such as process (in Node.js) and window (in browsers). You can bind any value to these already defined global variables, and you can access them from anywhere inside the application. For example, let's add the NODE_VERSION value to the env property...

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