Forem: Jowel Tisso

Var, let & const

Jowel Tisso — Thu, 19 Aug 2021 10:41:59 +0000

So, what is var, let & const

These are the keywords used to declare variables in javascript.

Declaring variables is one of the most important and repetitive thing you will be doing in programming.

var message = "Hello world!";

Here, "message" is the variable created using the var keyword.

Similarlly, let and const is also used in the same manner.

Who is older?

Var is definitely the older one. Let and const was later introduced in ES6(2015) version of javascript, keeping some drawback of var in mind.

What kind of difference do they have?

They have difference in scope, re-declaration and hoisting. In simple words, the accessibilty of variables (scope), the ability to manipulate the variables (re-declaration / update) and the mechanism of moving variable to the top before code execution (hoisting).

So, lets dive into the difference now!

Scope : Scope is basically a location from where a variable can be accessed or used.

Types of scope : (a) Global scope (b) Function scope (c) Block scope

Var :
Var is globally scoped or function scope. Which means if a variable is declared outside of a function then it is globally scoped i.e it can be accessed globally or it can be accessed from any portion of the code.

    var message = "Hello";

    function showMessage(){

      console.log(message); //output "Hello"

      //The message variable can be used here
    }

      console.log(message); //output "Hello"

      //The message variable can be used here

And if a variable is declared inside a function then it can only be accessed within that function.

    function showMessage(){

      var message = "Hello";

      console.log(message); //output "Hello"

      //The message variable can be used here
    }

      console.log(message); //output "message is not defined"

      //The message variable cannot be used here

Let & const :
Let & const variable is block scoped. Block means the area of code which is wrapped with curly braces {} is called block.

      function blockFunc(){

        //This is a block area

      }

      if(condition){

        //This is a block area

      }

So, let & const variables which is declared inside a block can be accessed only within that block

      if(condition){

        let message = "Hello";

        const greeting = "Welcome";

        //message variable can be used here

        //greeting variable can be used here
      }     

        //message variable cannot be used here

        //greeting variable cannot be used here

Re-declaration or update : Here we are going to see the ability to re-declare or update the value of a variables

Var :
Var can be re-declared and updated.Which means we can re-declare a variable with new value or update the value of a variable.

      //re-declaration

      var message = "Hello";

      var message = "Welcome";

      console.log(message); // output "Welcome"

      //update

      var message = "Hello";

      message = "Welcome";

      console.log(message); // output "Welcome"

Let :
Let cannot be re-declared but it can be updated.Which means we can update the value of a let variable. If we try to re-declare the variable then it will give us an error.

      //re-declaration

      let message = "Hello";

      let message = "Welcome";

      console.log(message); // output "message has already been
      declared"

      //update

      let message = "Hello";

      message = "Welcome";

      console.log(message); // output "Welcome"

Const :
Const can neither be re-declared or updated. Its value remains constant. So, it is necessary to assign a value when declaring a const variable.

      //re-declaration

      const message = "Hello";

      const message = "Welcome";

      console.log(message); // output "message has already been
      declared"

      //update

      const message = "Hello";

      message = "Welcome";

      console.log(message); // output "Assignment to constant 
      variable"

Hoisting : It is a process of moving all the variable declarations to the top of a scope before code execution.

Var :
Var is hoisted to the top of its scope and initialized as undefined.

      console.log(message); // output "undefined"

      var message = "Hello";

Technically, a variable should not be able to access before declaration but due to hoisting this is possible

      // Under the hood the above code works as

      var message = undefined; // This line is written due to 

      hoisting

      console.log(message); // output "undefined"

      var message = 'Hello';

Let :
Let is hoisted to the top of its scope like var but it is not initialized.

     // So, if you do this it will give you an error.

      console.log(message); // output "Cannot access 'message' 

      before initialization"

      let message = "Hello";

      //Under the hood of the above code.

      let message; // This line is written due to 

      hoisting

      console.log(message); // output "Cannot access 'message' 

      before initialization"

      let message = "Hello";

Const :
Const variables are hoisted to top as well but not initialized, just like let. So, it gives the same error as let if you try to access a variable before declaration and initialization.

      // So, if you do this it will give you an error.

      console.log(message); // output "Cannot access 'message' 

      before initialization"

      const message = "Hello";

So, finally these were the differences between an old var and the new let & const.Hopefully it has given you an insight in what they really are.

Few of the useful resources that I use as programmer

Jowel Tisso — Sun, 05 Jul 2020 20:07:26 +0000

When I started as a beginner I didn't know what things to use, how to use, what to read & where to read which would help me in my learning phase and make my journey a little smoother.

So, Initially my journey was rough, most of the beginner's journey are I guess. But slow and steadily I started stumbling upon some of the resources which I was very intrigued about and wondered if I knew about it long before.

Some of the resources was introduced by tutorials from either YouTube or some courses online or from reading some blogs.
I still remember, I felt like I had discovered a new tool for me to be greater at paths.

I'm being too dramatic I know, you can ignore that.
Well I feel I should share these resources so that any beginner who might be looking for it may stumble into this post and stumble less in their path to greatness.

So, these are the list of some of the resources that I use(random orders) :

Json pretty print
- It is used to format a compacted json document into a human readable format.
Markdown github guides
- It consists of basic markdown syntax which is used mostly and i refer to it when not in mind.
Codesandbox
- An online code editor just like vs code, how cool is that. You can edit online, save online, push changes to respostiory online and what not. This is a must try resource.
Coggle a mind map creator
- This is one of the best i came across, It is so satisfying to be able to arrange your thoughts and ideas so systematically. When some might prefer pen and paper to be the best, but this saves time and it makes things so easy and appealing.
Android material Io color tester/picker
- This is for Android developers, here you can test out color palettes in the layout like it would appear in the real device.
Online sqlite database reader
- It is used used to read .db file which is an sqlite database file.
Color palette picker
- It is a overall color palette selector, you can select and customize custom color palettes.
Online picture resizer
- This is very helpful as i have to work a lot with pictures so it saves my time and does the work with less effort.
Github markdown emojis
- These are github emojis if one would like to use it, this is for fun.

So, hope these resources help you in anyway and will keep on updating if I come across any more. Till then see you in next stumble.

Importance of fitness for a Busy person

Jowel Tisso — Sun, 05 Jul 2020 18:56:12 +0000

Often we ignore the health part in our life as we are too busy in our day to day activity or we are too lazy from getting out of our bed.

At an early age our body seem so heavy when trying to get up from bed and wished we could sleep for few more hours.

But what we all don't realize is that all this laziness adds to the negative health effect we are gonna face in the mid of 20's and 30's.

As we all know, our body adapts to the environment and the behavior its being fed by us. So, our body particularly muscle and bones gets weak if we don't do any physical activity as it has no reason to be strong.

And that's what contributes in our health issues in our mid 20's or 30's as at these age we start facing the real world and start working which means no laying on beds for long, no extra sleep time, no wasting time watching movies.

So, when you start working actively and try to push your boundaries then your body starts answering, answering you with pain, many different ones like lower back pain, headache, neck pain and much more because you were not use to pushing yourself this hard.

Which prevents you from achieving your potentials and eventually cause health issues. So, staying fit is a part of our life every one knows that yet people fail to do so.

And when you are engage in jobs and are busy in work then it is much more hard to find time for it.

So, one must try to realize that taking care of our body is as important as breathing, as important as eating and as important as sleeping... for, one needs to gain full support of the body to prosper in life and to achieve what is to offer for oneself.

My first dive into programming with a game

Jowel Tisso — Sun, 05 Jul 2020 17:58:55 +0000

This all started in the year 2018 when i first thought of making a mobile game with no knowledge. Yes, zero knowledge.

I got inspired by watching a youtube video of how to make a game in unity. Why a game, I was very crazy for video games back then. I played for hours an enjoyed playing. I know everybody does. Games are really awesome especially when the graphics are breath taking.

So, when i came across that video it inspired me to try and make one so i followed the tutorial installed all the required software and started to work on it(Yeah)...

But... To tell you the truth i didn’t understand a single thing in that software(which was unity) and the codes i wrote in the beginning(all the complex calculations of physics and maths) it was in c# and I didn't had an idea what it was.?, I was just following the video like a dummy for few days. Man it was frustrating...

But then i followed more tutorials as i was eager to learn and at last built a game... Kind of... I wouldn’t call it a game, I don't know what to call it but for now let’s call it a game.

OK, now what I made, Big Time, It only walks and jumps, yes you heard me, It only walks and jumps. It is a game of an early man age. But yes, the character on my game can do a moon walk, unbelievable right.... Here it is...

Yes, I know the quality is poor but this is what I only have as a record of that moment.

But, after this game my whole journey of stepping into the world of programming began and eventually started learning different languages and frameworks. And now here i am developing Android and web app. A lot more better than when i first began.

So, this was it how it all began, Thanks for reading if you did.
This is my first blog so its kind of gibberish, hopefully will try to get better at it until then see you next time...