Understand JavaScript Engine phases and lifecycles of the “var”, “let”, “const”. Scopes, hoisting, closures simplified.

Free JavaScript Variables Lifecycles Online Training Tutorial

Free JavaScript Variables Lifecycles Online Training Tutorial

Limited Time Offers Only


  • 3 hours on-demand video
  • Full lifetime access
  • Access to mobile and TV
  • Certificate of Completion

What you’ll learn

  • Explain the difference between global scope, function scope and block scope
  • Understand how variables declared using “var” behave
  • Explain the difference between “let” and “const”
  • Practice different variables declarations types
  • Understand two JavaScript Engine Phases – “Compilation” and “Execution”
  • Deeply understand variables lifecycle phases for variables declared using “var”, “let” and “const”
  • Explain lifecycle phases for the undeclared variables
  • Understand lifecycle of the function
  • Practice and understand most important variables usage guidelines


  • Basic JavaScript knowledge
  • Fundamentals of CSS
  • Basic understanding of HTML


Do you want to understand the real difference between different types of variables in JavaScript?

Understand different types of scopes?

Want easily explain what is hoisting?

What about closures?

In this course, I will dive deep into the JavaScript and explain to you what happens under the hood when you declare any variable or function. You will understand what happens on the “Compilation” and “Execution” phases in JavaScript Engine.

I will make explain to you what is a variable declaration, initialization and assignment that are all-together called Variable Lifecycle Phases.

We will also focus on this course on the Variables Usage Guidelines:

Make Code clear and readable for others

Always declare variables before the first usage

Always use “use strict” globally

Don’t expose to the outer scopes local variables

You will also get several practical exercises where you will need to apply gain knowledge about different variables, hoisting, scopes and closures.

All exercises and code samples are available as Git repository.

Hope to see you onboard!

Who is the target audience?

Contact/Consult/Hire Front End JavaScript Developer