DEV Community: kuldeep patel

I need to work as part-time

kuldeep patel — Sun, 24 Jan 2021 11:45:41 +0000

Hii... There
I need to work part-time. I have experience in HTML, CSS, Boostrap, Javascript, WordPress, and Shopify. If you have any work for me please tell me...

How to declare variables in javascript? 🤔

kuldeep patel — Sat, 16 Jan 2021 03:45:34 +0000

Hi...!
In this article, we are discussing variables. There are different declared variables in different programming languages. Javascript is very freely declaring variables.

There is some different way to declare in javascript. But First

What are the variables?

Now you think about your purchase gift box. But the gift boxes are empty there is no value 😅. It looks like the above image ☝️
There is no value.

Now you put a toy in the gift box 🎁. The gift box is valued because you put a toy in the gift box. if you open the box you see there is a toy. 🤩
Here gift box we are call variable name and toy we are called value.
variable name is = gift box
variable value is = toy

the variable name holds the data and stores it.

How do I declare variables in javascript? can you tell me?

In javascript, you can declare variables in 3 ways.

using var
using let and
using const

var

First, we are trying with var variables. So var is stores data in memory for example
var fullName = 'Kuldeep'; using var keyword you are use-value anywhere in the program. Now you are using fullName anywhere in the howl program like console.log(fullName);🤪

let

Now second is the Let keyword.

Let keyword you also store data in javascript program. There are lots of think with the let keyword. Because with let you are store value multiple in one variable.
For example

let message;
message = 'Hello kuldeep 👋';
console.log(message);

There are messages that hold one think Hello Kuldeep 👋. But if you want to store data in one variable you can also do that.

let user = 'Kuldeep', age=25, message = 'Kuldeep Hello'
console.log(user);
console.log(age);
console.log(message);
In older scripts, you may also find another keyword: var instead of let:
var and let work as same but var are the old way to declare now a new way to hold store data let keyword.

But if you are declaring a variable already and you have put another variable value what happens when you try like this.
let fullName = 'Kuldeep';
and now
let fullName = 'Jone';

What happened when you run 👆 in this program.

There are show errors 🥴. O nooo because fullName is already declared in the program

I have an error in the console.
Uncaught SyntaxError: Identifier 'fullName' has already been declared

Now we are talking about rules about how to declare a variable and variable name.

1st: Variable name does not start with a number and # keyword.
var 1name='kuldeep';❌
var #name= ''❌
👆 this is wrong to declare a variable in javascript.

2nd: Variable name start with A-z, $, _
let firstName = 'Oliver';✅
let _secondName = 'kuldeep';✅
👆 this Right way to declare a variable

3rd: You are not using - in javascript
let first-name='Jone';❌
👆 this is wrong to declare a variable in javascript.

4th: CaseSensitve word.
let first = "kuldeep"; and you write let fiRsT ='Oliver';
👆 There is two different variable name first and fiRsT are to the different thing in Javascript.

5th: We do not use reserved keywords in javascript
var let='kuldeep';❌
let const = 'Oliver';❌

Const

const keyword also works as let keyword.
If you have any queries about this article you can comment below

How to debug your code in javascript?

kuldeep patel — Sun, 03 Jan 2021 11:18:10 +0000

Hii DEV family 👋

In this article, we are discussing debug your code in javascript sound is good!. Let's start
Debugging your code is very important to solve a problem.
Ya yaa Error...! 🤯

Lifelike an error. 😂

Now how to solve it?
Console.log is helping to solve the error.
There are so many types to see the output in the console.

console.log

it's very simple and basic use in javascript programmer...!
ex:1
console.log("🤪");

ex:2
var name = 'Kuldeep';
console.log(name);
If you want to basic way to see an error you can go with it.

But what if we have multiple values that we want to log?

For example:
var name='kuldeep 🤓';
var friendName='Pawar 😝';
var car = 🏎️;

console.log(name);
console.log(firendName);
console.log(car);

That time we are console.log() 3-time write? No, I have an idea 💡.

I write code like this.
console.log('name'.name, 'My Friend Name'.firendName, 'car'.car);
But this is also long 😆
I write code like this again...
console.log( {name, firstName, car} );

You can write this way your code line is less and you can easily understand to code what is. And You are a smart way programmer.

Let's work with Object:

let car ={
carName: 'BMW',
carColor: 'Black',
price: $250000,
}

console.log(car);
console.log({car});

The first log will print the properties within the car object. The second will identify the object as "car" and print the properties within it.

Variables within the log

console.log('%s is %d years old', "Kuldeep", 29 );

in this example, %s is referred to as string options, and %d is referred to as any number. In this example our output statement is a show like this: Kuldeep is 29 years old.

variants log().

There are a few variant logs. Mostly widely use console.log(). But there is also.

console.info('This is info message') ;
console.warn('Please enter valid number');
console.error('number is not valid');
console.debug('This is debug');

warn print as yellow color and error message print as red color

console.table()

console. table() is view beautiful table view with index number.

let animal = [
    {
        cow: "🐮",
        cat: "🐱"
    },
    {
        dog: "🐶",
        monkey:"🐒"
    }
]

How to write a javascript program.?

kuldeep patel — Sun, 03 Jan 2021 05:43:36 +0000

we need 2 things to run the javascript program...

We need Code editor and -> We are using vs (Visual Studio) Code. VS Code is free to editing code. Vs code is developed by Microsoft developers.
We need where to see our output? -> We use for output is Chrome. Chrome is developed by Google so it's also free to use 😅.

These 2 stuff things you already know.

So in this article, we are writing our first javascript program... 🥶. No Today we are not writing a Hello world... We are writing with Emoji to fun with javascript. Because I'm not thinking you go boring javascript.
Every javascript line end with ;

We are writing two types of javascript code. Internal and external javascript code.
first, we are discussing internal javascript

So now you see in our code. First, we make a simple HTML program, and then after you want to write javascript code. Then you can use <script></script>.
You can use the <script> tag inside the <body> tag Or <head> tag

Secondly, External javascript use.

Index.html

script.js

Now you can see the first Index.html we are linked with the external script.

<script src="./script.js"></script>.

SRC is an attribute of the script tag. Using src you can connect with an external javascript program. And seconde file call script.js in this file we write simple code...!

Now, How do I see my output in the browser.?
If you are using Chrome, Firefox, Or any other browser the way is always one.

Open Chrome browser -> clicks on white background -> Go to Inspect

Go to the console.

Here our output 👇

This is a long process to see our output 🤣
Click F12 to directly open the console in your browser... 😎...

What is console.log()?

The console.log() is a function in JavaScript that is used to print any kind of variables defined before in it or to just print any message that needs to be displayed to the user.

We discuss more Console.log() in the next chapter...
Thank you for reading 😉

What is Javascript?🤔

kuldeep patel — Fri, 01 Jan 2021 13:48:27 +0000

Hi everyone...!
Happy New year...
This is my first post in DEV.😅

So let's start. 🏎️

Javascript now a day is a very useful and creative thing in the world. I love javascript because it's very easy to understand, readable.
Javascript working with AI and ML

So are you confused about how do I start programing language?
Don't worries you can start with javascript.

You think you heard this word Java. Right!
Java and javascript are different things in the programming world.

Java

java is a statically typed language
java is class-based work
java uses block-based scoping
java uses in the android app.

Javascript

javascript is dynamic.
javascript is a prototype-based worked.
javascript uses a function-based scoping.
javascript uses in website design, web app.

In short one line different java and javascript are like car and carpenter.

I hope it is helpful for you. If you want to learn about more javascript then follow me. We are going step by step.