Day 8 – Var vs Let vs Const -Learning Node JS In 30 Days [Mini series]

Today we’re going to learn about var vs let vs const

Before ES6 VAR was the King. We used var in everywhere we wants to declare a variable

var variables can be re-declared and updated

Now we divide var with two different types one CONST & other LET

CONST is declared for those value which will not changed anytime! Or will not be updated at any point. const cannot be updated or re-declared, this will lead you to an error you if try

We use LET when their is a change of updating the variable

LET can be updated but not re-declared. This will give a error you can’t run code

So in es6 we use LET & CONST not Var!

Do you knew this before ?

You can see the graphical version here

Originally it published on nerdjfpbblog. You can connect with me in twitter or linkedin !

You can read the old posts from here --

Day 1 — Introduction - Learning Node JS In 30 Days [Mini series]

Muhammad Ali (Nerdjfpb) ・ Dec 4 '19 ・ 1 min read

#node #javascript #codenewbie

Day 2 - Install and Running Node on Window - Learning Node JS In 30 Days [Mini series]

Muhammad Ali (Nerdjfpb) ・ Dec 5 '19 ・ 1 min read

#node #javascript #codenewbie

Day 3 - JavaScript Engine - Learning Node JS In 30 Days [Mini series]

Muhammad Ali (Nerdjfpb) ・ Dec 6 '19 ・ 2 min read

#node #javascript #codenewbie

Day 4 - Window === Global ? - Learning Node JS In 30 Days [Mini series]

Muhammad Ali (Nerdjfpb) ・ Dec 7 '19 ・ 2 min read

#node #javascript #codenewbie

Day 5 - Function Declarations vs. Function Expressions - Learning Node JS In 30 Days [Mini series]

Muhammad Ali (Nerdjfpb) ・ Dec 8 '19 ・ 1 min read

#node #javascript #codenewbie

Day 6 - Require & Module - Learning Node JS In 30 Days [Mini series]

Muhammad Ali (Nerdjfpb) ・ Dec 9 '19 ・ 2 min read

#node #javascript #codenewbie #tutorial

Day 7 - More Modules - Learning Node JS In 30 Days [Mini series]

Muhammad Ali (Nerdjfpb) ・ Dec 10 '19 ・ 2 min read

#node #javascript #codenewbie

Comments

[Adam Crockett 🌀]

I constantly use const, but don't let me get started on this subject, I varely use var. 🥁

[Muhammad Ali (Nerdjfpb)]

That's good! Var was mainly used before const and let.