/javascript-bundle

Tutorials to learn the JavaScript programming language.

Primary LanguageJavaScriptMIT LicenseMIT

JavaScript Course

Tutorials to learn the JavaScript programming language.!!

  • Hello, Java Script!!

  • Variables and Types

  • Arrays

  • Manipulating Arrays

  • Operators

  • Conditions

  • Loops

  • Objects

  • Functions

  • Pop-up Boxes

  • Callbacks

  • Arrow Functions

  • Higher Order Functions

  • Map Filter Reduce

  • Object Oriented Concepts

  • Day 1 : JS Execution Context and Basic Concepts

  • Day 2 : Hoisting

  • Day 3 : let,const,var and Scope

  • Day 4 : Closures

  • Day 5 : setTimeout Functions

  • Day 6 : Higher Order Functions

  • Day 7 : Callback Functions

  • Day 8 : Event Loop Concepts

NOTE : JS can behave as an interpreted or a compiled language depending upon the JS Engine. It was written initially to be used as an interpreter as it is mostly used in web browsers but later it is used as both. So, it is called a JIT(Just-in-time) language.

JS Engine

  • JS runtime environment consists of JS Engine, Web APIs, Event Loop, Callback Queue, microtask queue. JS Engine is the heart of JS runtime environment. Browser can only execute the JS code because it has JS runtime environment. Node.js has JS runtime environmet

  • Different browsers have different JS Engine. For example Microsoft Edge: Chakra, Mozzila Firefox: Spidermonkey , Google Chrome: V8 according to the ECMA script.

  • The first JS Engine was spidermonkey which was breated by creator of JS.

  • JS Engine Architecture a. Code Parsing b. Compilation c. Execution

  • Syntax parser generates AST(Abstract Syntax Tree) which is produced after parsing level.

  • After the parsing, the compilation and execution go hand-in-hand. During compilation phase, AST is interpreted and during this time it is also converted to the optimized code by the compiler. So, the role of the compiler to optimize the code as soon as possible during the run time.

  • Memory heap is a space where all variables and functions are assigned memory. It is in constantly sync with the call stack and the garbage collector.

  • Garbage Collector frees up the memory heap whenever required. It uses Mark & Sweep algorithm to sweep off unnecessary stuffs from the code.

JavaScript Project-1

  • Color Flipper Project : Select Random color