DEV Community: Roshan Shambharkar

Top resource's to learn JavaScript

Roshan Shambharkar — Sat, 07 Sep 2024 07:25:00 +0000

In the world of internet you will find such resources which will help you in learning JavaScript, well. I am going to tell you about some such resources which I have personally used.

Udemy JavaScript in Action JavaScript Projects
In this Javascript course you will learn how to make a AJAX calls, you will get 35 pages PDF where you will be guided on how to do coding

JavaScript: The Definitive Guide: Master the World's Most-Used Programming Language
This is a book where fundamentals of JavaScript are explained very well

If you want to know more about these two resources, you can ask me in the comment section

Types of Variables in Java

Roshan Shambharkar — Fri, 09 Aug 2024 08:06:57 +0000

In Java we have three types of variable called instance, local and static

Note:- In Java we didn't support global variables

Instance variables

Instance variables are those variables which we define in the class out not in method

public class A {
   String name;
   String color;
}

in the above example in class A we defined some variables using data type in the above code snippet we had define instance variables inside the class but out side the method these variables are instance variables if you want access instance variables outside the class then you have to use access specifier public instance variables scope depended upon access specifier

Local variables

A variables used while method declaration passing method augments or parameter or declaring variables in side method body called as local variables

public int caluclate(int a, int b) {
  return a + b;
}

In above code snippet variables declare in method called as local variables you can only use this variable only inside the method

*Static variables *

static variables defined using static keyword after declaring static static keyword in front of your variable the variables called as static variables

public class B {
  static String name = "Ryan";
}

The above code snippet is a example of static variables

What is Mark up languages

Roshan Shambharkar — Fri, 09 Aug 2024 07:30:12 +0000

Whenever we talk about markup language, the name HTML comes to our mind but it is not so, HTML is not the only language. Today I will tell you about some markup technology. HTML, Markdown, and restructuredText. we all know about HTML but Very few of know Markdown and restructuredText

so basically Markdown and restructuredText languages are those languages that annotates ** text so that computer can manipulate for some task, Most markup languages are readable by humans and are designed to be written with plain text no need to use some editor like MS-word or notpad
This website blog which one you are reading now is also some markup annotation like for making text bold you can use double asterisks `bold**`

Most markup languages have set of elements including's following

Paragraphs
Title
Headings and subheadings and subsubheadings
bullet lists
numbered lists
tables of data
figures or images
text that is bold, or italic
page headers
page footers

What is JavaScript JSON📖

Roshan Shambharkar — Sun, 23 Oct 2022 08:27:09 +0000

✔ JSON stands Form JavaScript Object Notation(JSON), JSON is Text Based Data Format, that is used to store and transfer data,
it is usually useful to sent to data server to webpage,

Syntax of JSON

{
 "MoviesStar":[
  {"firstName":"John","lastName": "cena"},
  {"firstName":"linda","lastName": "Friday"},
  {"firstName":"Teresa","lastName": "Plamer"},
]
}

🔴This above JSON Syntax defines movie star name object: an array of 3 moviestar record

⭐In JSON data stored in KEY/VALUE Pair separate by comma,

✨JSON DATA

JSON data is written as name/value pairs, just like JavaScript object Properties, A name and value pair consists of field name(in double qoutes), followed by a colon, followed by value,
e.g "name": "Tony"

JSON Objects

The JSON object is written inside curly braces{}, JSON objects can contain multiple key/value pairs,

for e.g :-

{
   "firstName":"Tony",
   "lastName": "stark"
}

JOSN Arrays:

JSON array is written inside square Brackets[].
for e.g:-

//JSON array
["audi", "BMW", "jaguar"]


//JSON Array containing  objects
[
  {"name": "Tony", "age": 48},
  {"name": "Peter", "age": 20}
]

🚫Note:
JSON data can contain objects and arrays. However, unlike Javascript objects, JSON data connot contain functions as value.

⭐Accessing JSON data
We can access JSON data using the dot notation LIKE this,

//JSON object
const data = {
"name": "john",
"age":  22,
"hobby": {
"reading": true,
"gamming" false,
"sport": "football"
},
"class":["JavaScript", "HTML", "CSS"]

//accessing  JSON object
console.log(data.name); //john
console.log(data.hobby); //{"reading": true,"gamming" false,"sport": "football"}

console.log(data.hobby.sport); //football
console.log(data.class[1]); //HTML
}

Some Shocking facts About JavaScript 💻☕

Roshan Shambharkar — Sat, 22 Oct 2022 06:23:41 +0000

fact 1. JavaScript Was Originally named mocha, But after some time it is used to called Live Script and some period of time people start calling javascript.

Fact 2. JavaScript Was created in 10 Days.

Fact 3. Function can call Themselves, In javaScript function call themselves
for e.g

(function() {
 console.log("I am a function");
})(); // I am a function

Wrap Function between () and immediately call it with empty bracket (). they called as IIFE it means Immediately Invoked Function Expression

Facts 4. ; In JavaScript You can write a Program Using semicolon;

In JavaScript, You can use semicolon in the startas well as at the end of the statement but it is not recommended but you can use it try it and let me know in comments section

Fact 5. Undefined is not a reserved

Undefined is not reserved word in javascript, because it has very special meaning and by using undefined you can determine a variable is undefined it is only way to defined variable is undefined and you can use it as identifier.

var undefined = "I am undefined";
console.log(undefined);
//I am undefined

What Are the Tokens In JAVA

Roshan Shambharkar — Thu, 29 Sep 2022 06:51:01 +0000

What are the tokens in JAVA.
Tokens:- Tokens are the smallest unit of programming language which helps the the programmer to create instructions

Tokens are two types
1- Keyword:-
2- Identifier:-

Keyword:-

compiler aware words are called keyword
Keyword have predefine meaning and cannot be altered by programmer's
All Keywords are written low case.

Identifier:- Identifier are the names given by the programmer to the members of java such as class name, method name, variable name, interfaces name, packages etc.

There are certain rule to follow while naming the identifiers
if the rules are not followed we get complie time error(rules are checked by complier)

Rules to name Identifier
1- An Indentifire cannot start with number
e.g 1Programm ❌
Program1 ✅

2- Character spaces are not allowed while naming the identifiers
e.g My First Program ❌
MyFirstProgram ✅

3- Special character are not allowed while naming the Identifiers other than '$' and '_'
e.g $Programs ✅
_Program ✅

4- Keyword cannot be used in Place of Identifiers

Structure of Java Program

Roshan Shambharkar — Sat, 24 Sep 2022 04:36:40 +0000

Structure of Java Program

class ClassName {
 public static void main(String args[]) {
 //statements
 }
}

Let's look at the elements involved in the structure of a Java program.

A typical structure of a Java program contains the following elements:

class Block:- Methods and Variables can be written in class Block

Methods Block:- Statement and instructions written in method block

*Steps to Create, Complie and execute java Program *

Stpe-1. Write A programm using editor and IDE

Editor : -
1. Notepad
2. Word
3. Notepad++
4. Edit plus
5. Sublime
IDE:-
1. Eclipse
2. Intelji
3. Visual Studio code
4. Net Beans

Using the above code editor we write programs and save the file using .java extension

Step-2. Compile the code or complie the java file
complier complie the code complier check's for the syntax(rules) if the syntax is correct is generated the class file if the syntax's is wrong it does not generate the class file but its throw complie time error

Step-3. excute the class File

Syntax of print Statements

System.out.println();
1. This print statement will print the data as push the cursor to next line
System.out.print(); This Print Statement will print the data and cursor will stay in same line

Now Write The below code in any editor

class MyProgram {
 public static void main(String args[]) {
 System.out.println("Hello World!");
  }
}

Command to complie java program
javac MyProgram.java

command to excute java program
java MyProgram

Note:- To check the version of JDK
javac -version

How To Read a local JSON File Using Fetch API

Roshan Shambharkar — Sat, 24 Sep 2022 04:16:10 +0000

How To Read a local JSON File Using Fetch API

Can I use Fetch on a local JSON file?

The standard method that can be used to read
JSON files (either locally or uploaded to a server) is the Fetch API.
Use the same syntax for both. The only difference is the URL

First Create A .JSON file With name test.json

{
"countries":[
{
   "name": "Indonesia",
   "capital": "Jakarata"
},
{
   "name": "Philippines",
   "capital": "Manila"
  }
 ]
}

Then create JavaScript file give name fetch.js

fetch("test.json")
.then(response => response.json())
.then(data => showInfo(data));

function showInfo(data) {
console.table(data.countries);
}

What is JDK Architecture in JAVA

Roshan Shambharkar — Thu, 22 Sep 2022 05:09:34 +0000

JDK Architecture

JVM:-

JVM Stands For Java Virtual Machine it is an interpeter which is use to convert byte code to machine level languages line by line
JVM is present in JRE

What is JRE?

JRE stands For JAVA RUNTIME ENVIRONMENT
It Consists of JVM And built in library files which is use to executes JAVA Applications
If We want to only execute Java Applications we need to install JRE
JRE is Present In JDK

JDK:- JAVA Development Kit

JDK stands For java Development Kit
it is a package given by oracle community.
Which is use to develop as well as run java software execution
JDK consists of JRE and Development tools

Note:- JDK is Platform Dependent, software made by JDK are Platform Independent

Platform Dependent VS Platform Independent

Roshan Shambharkar — Wed, 21 Sep 2022 05:28:47 +0000

Platfrom
It is a combination of certain hardware and software,
components in which apllication will run.

Software's are two types
1) Platform Dependent software's
2) Platform Independent Software's

1) Platform Dependent Software
The software which is can run on only one type of platforms are called as platform Dependent software
For e.g :- Software made up of C and C++

Now Quetions is Why software made up of c++ and c language

1) When a programmer tries to define software using c++ and c language and saves the source code using .c extension

2) and when he tries to complie this .c file using a c compiler the c complier converts .c file into .exe file
3) the .exe
file contain native machine level code which can run on only the
native type of platform

4) The .exe
file contains native code which one also called executable code

5) This native code connot be executed in different platforms such as mac, linux, solaris etc

6)Hence software made of c and c++ language are platform Dependent

Platform Independent software

The software which can run on any type of platform are called as platform Independent software For e.g:- software made of java, python, .net

1) When Programmer design a software and compiles it using java compiler the java complier converts the java file into .class files this .class files contains byte code

2) The .class code present in class file are also non executable codes and they are called intermediate code

3) This byte code is neither understand to programmer nor the computer

4)To run the byte code in any type of platform we need to install a software know as JVM

5)JVM is used to convert the byte code into machine understandable language

6)Hence with the help of byte code and JVM we can run java software in any type of platform

7)This is the way how java software achive software independency's

Top 5 Text Books will help you to learning Programming 📚

Roshan Shambharkar — Sun, 11 Sep 2022 04:14:23 +0000

There are many amazing programming books and computer science books out there.

Many of the best programming books are used by college and professional developers to improve their skills. It's safe to say that once you learn how to code yourself, you can't just pick up a top programming book and do the same.

Which programming book should I start with?

5. Inside the Machine: An Illustrated Introduction to Microprocessors and Computer Architecture

The central processing unit or microprocessor is the heart of programming as it is responsible for executing the instructions of a computer program.

This excellent programming book will help you understand the fundamentals of modern computing by learning about the different parts of computer architecture and what goes on behind the scenes of programming. Start with basic concepts and progress to advanced concepts.

4. C Programming Language, 2Nd Edn Paperback

The book itself is great and intuitive to teach you C programming and also could be used as a reference manual, I read only basics Part . You can go for it but, I Liked the way it is written, straightforward and to the point.

A 50 year old language and still people love it
This Language is my personal favourite, I was waiting for the International edition but I completed that book in O’Reilly so bought this Indian edition, trust me you wont regret ever, every page is authentic

3. Beginner's Step-by-Step Coding Course: Learn Computer Programming the Easy Way Hardcover

The simplest, most visual introduction to coding for adults.Using a graphic method to break complex subjects into user-friendly chunks, computer coding has never been easier thanks to this programming book. Here's what you'll find inside the pages of this coding for beginners book:- To reinforce learning, practical coding projects are followed by suggestions and challenges for the reader,

Suitable for both children and adult beginners. The design of the book makes it easy for the mind and brain to understand the content. A very well thought out and well planned book.

2. Web Technologies: HTML, JAVASCRIPT, PHP, JAVA, JSP, ASP.NET, XML and Ajax, Black Book: HTML, Javascript, PHP, Java, Jsp, XML and Ajax, Black Book

If You are getting into web dev it is a good book to start with.
The HTML part and the javascript part is so well explained.

Too good book if You want to learn frontend and backend both then this book is for You this book also contain jdbc which is a important part of web technolgy.

1. Cracking the Coding Interview: 189 Programming Questions and Solutions Paperback

Best book for the programmers who want to get started with the data structures and algorithms.
Problems are well chosen

Not the one stop resource but should be complemented with other resources. Good to go through during the initial and final phases of preparation

For software developers, this is the most important purchase.

Check out our YouTube videos for tips and tricks. No need to move from cover to cover.

My approach: choose the chapters according to their priority, solve only the odd or even problems, and just set with this marked problem, the odd one, going to the next chapter on the list.

And most importantly, take a pen and give her half an hour to each problem, even if you don't know how to solve it. If you want to develop algorithmic thinking, don't jump to the solution page.

== Vs === confusion Solve...🌟

Roshan Shambharkar — Sat, 10 Sep 2022 11:33:13 +0000

Before knowing the difference between "==" vs "===" in JavaScript lets know about what are the == and != operator.
== vs !=
so the double equals (==) operator use to check if two values are equals and not equals (!=) if the two values are not equal
and its return type is always boolean like true **or **false.

In == and != both operater do type conversion before comparing the elements For e.g : - 2 == '2' so in this == operate do type conversion implicitly like before comparing it will do implicitly type coercion like 2 == Number('2') and then it will show output as *true **so this is what happens when we compares using == operater before showing output it add string '2' value in number fucntion and convert into number 2 and the comparing's we get the output as a true which 2 == 2
**for E.g *

let xxx = 2;
let xxxx = '2';
console.log(xxx == xxxx);// true

Now Check with === operater is also called as strictly equality operator thats means it will not do any type conversion internally

For E.g:

let x = 1;
let y = '1'
console.log(x===y)// output will false