This topic is very very important in javaScript. It is an unknown behavior of javaScript. Shortly, javaScript compiler moves variables and function declarations

Hoisting is JavaScript's default behavior of moving declarations to the top of the current scope.

Variables and constants declared with let or const are not hoisted!

JavaScript Declarations are Hoisted

In JavaScript, a variable can be declared after it has been used.

In other words, a variable can be used before it has been declared.

Hoisting applies to variable declarations and to function declarations.

function declarations are hoisted before variable declarations.

Hoisting is only possible with declaration but not the initialization. JavaScript will not move variables that are declared and initialized in a single line.

I sometimes try to remember basis of JavaScript Functions. So, I often exercise about it. I followed this link https://www.w3schools.com/js/js_function_definition.asp. I copied some important descriptions from that link. My aim is to follow this post when I need to remember again 🙂

JavaScript Functions

A JavaScript function is a block of code designed to perform a particular task.

A Function is much the same as a Procedure or a Subroutine, in other programming languages.

Why Functions?

You can reuse code: Define the code once, and use it many times.

You can use the same code many times with different arguments, to produce different results.

JavaScript Function Types

1. Function Declaration (function statement)
2. Function Expression
3. Function Constructor
4. Self-Invoking Function (Immediately Invokable Function Expression IIFE)
5. Arrow Function
6. Object Method Shorthand Definition
7. Generator Function