DEV Community: ViGnEsH

Two mine projects in javaScript

ViGnEsH — Thu, 30 Apr 2026 17:11:43 +0000

April/30/2026

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DOM

ViGnEsH — Tue, 28 Apr 2026 08:31:43 +0000

April/28/2026

1.What is a dom ?

DOM from is documents object model. it is used for responding website create

2.What is Document Object ?
document is the root object to access the page.

3.Tree Structure ?
The HTML page is represented as nodes (elements, text, attributes).

4.Who to modify html page ?
You can add, remove, or update elements, styles, and content. used like object.

5.How do you select elements in the DOM?
Document.getElementById, Document.getElementByclass ect..

What is the difference between DOM and BOM, and how do window and document relate? (TBD)

What is the difference between NodeList and HTMLCollection?(TBD)

Tell me about yourself

ViGnEsH — Tue, 21 Apr 2026 07:00:10 +0000

April/21/2026

I'm K Vignesh,
I am a comfortable professional front-end developer,
I know about HTML, CSS, and JavaScript,
I complete fure project in HTML and CSS, and I know about JavaScript programming, scenario questions,
My ambition is to be a web developer, and I do my code push in GitLab, also write blogs in every day.

Variable, operations, conditional statments PART 2

ViGnEsH — Sun, 19 Apr 2026 06:01:04 +0000

7. Even or Odd

Output

check a number odd or even code this
if condition number modulus 2 ===0 is even condition fail go else condition run

8. compare two passwords

Output

Check a password and repassword same print successfully

else print incorrect password.

9.Eligible to vote

Output

Eligible to vote is age 18 is starting age for vote

10. checked logged and admin

Output

Check a logged and admin is correct go inside

11. Total cart amount

Output

Calculator in a and b value in function

12. Greeting function

Output

create a function is name print in data

13. Temperture conversion

Output

Formal F=(CX9/5)+32

14. Largest number

Output

largest only give

15.EMI

Output

This is calculator in emi for price, rent, tax

16. Admin

Output

Admin only entry

17. positive, negative, or zero

Output

Here, is positive(1,2,3...), negative(-1,-2,-3...), or zero(0)

*movie ticket pricing *

Output

movie ticket price is chid 12 less than 100 more than age 200

20, Grade A, B, and fail

Output

Here, than grade A 90, grade b 75, fail less than

Variable, operations, conditional statments

ViGnEsH — Sat, 18 Apr 2026 06:59:32 +0000

April/18/2026

Output

We are used : Function Expression
username and password corrent only print Login successfully
username one wrong print invalid username
password only wrong print invalid password
username and password both wrong print invalid username and password.

2. Product details

Output

We are used : Function Expression
Product details : three varibles store data comma varibles
like : console.log( variblesName , "String" ,variblesName, "String",variblesName, "String")

3. student mark

Output

We are used : Function Expression
three varibles store data used arithmetic operators +

4. swap number

Output

We are used : Function Expression
Student: two varibles swap two number and store.

5. Login status

Output

We are used : Function Expression
used data types in booleans true or false

Object & Array Scenario Question

ViGnEsH — Fri, 17 Apr 2026 07:24:27 +0000

April/17/2026

1. user profile update

Output:

2. shopping cart total

Output:

3. find specific object

Output:

4. add item to array and filter

Output:

5.count items in object

Output:

6. convert array to object

Output:

7. Group users by role

Output:

7.TBD

Array Iteration Methods in JavaScript

ViGnEsH — Thu, 16 Apr 2026 07:32:45 +0000

April/16/2026

Array Iteration Methods.

JavaScript Array Iteration methods perform some operation on each element of the array. Array iteration means accessing each element of an array.

Array Iteration Methods.

arrayName.forEach
arrayName.map()
arrayName.flatMap()
arrayName.filter()
arrayName.reduce()
arrayName.reduceRight()
arrayName.every()
arrayName.some()this method is used the same for every method(TBD)
arrayName.from() (TBD)
arrayName.keys() (TBD)
arrayName.entries() (TBD)
arrayName.with()
arrayName.Spread(...)
arrayName.Rest(...) (TBD)

*1. arrayName.forEach *

The forEach method calls a function as a callback function once for each element. The forEach method has no return values.

The function takes 3 arguments:
values, index, array

Here, the arrow function is used in a score(values), count(index), and array(array).

2. arrayName.map()

The map method calls a function as a callback function once for each element. The map method has given a return value, and the main element has not changed, giving a duplicate.

Here, the arrow function is used in a score(values), and duplicate values are multiplied by 10.

3. arrayName.flatMap()

The flatMap() method first maps all elements of an array, and then creates a new array by flattening.

Here, the arrow function is used in a score(values), in an arrayname values, and copy values.

4. arrayName.filter()

The filter method, less than <, and greater > than are used for objects

Here, fewer than 35 values give me.

5. arrayName.reduce()

The reduce() method for the array elements, one by one, to give a single value, and the method works from left to right in the array

Here, the arrayName value is total.

6. arrayName.reduceRight()

The reduceRight() method for the array elements, one by one, to give a single value. The method works from right to left in the array

Same for the reduce method, but value added right to left.

7. arrayName.every()

The every() method is used in Boolean values for objects.

Here, a Boolean value gives a true or false. score less than 35.

8. arrayName.some()

The same method is used for Boolean operations for every method.

Here, a Boolean value gives a true or false. score less than 35.

9. arrayName.from()

12. arrayName.with()

The with() method is a replacement, to array elements

13. arrayName.Spread(...)

The spread method used for the two-array merge converts a single array value.

Here, ...three dots are used to give a full element.

Call back function_Single Threaded_forEach

ViGnEsH — Tue, 14 Apr 2026 05:03:19 +0000

April/14/2026

Call back function

A callback function is a function pass is go another function in agrument is excuted leter.

A function can accept another functiona as a pass.
Callback allow one function to call another at later time.
A callback can excuted afer another function has finished.

Here, name()is passed a callback to name1(),which excutes after the name.

Single Threaded

JavaScript run in single thread.

It can only exceute one task event task.
Multi task in one program there are one by one run speed.
A issues sometime support have a task is a time consuming.
One block run start next one.

forEach

This is a array method only used array.
A javaScript array forEach is built in method used excuted of provided funcion one for a element in a array

normal function:

Arrow Function:

Here, automatically create value, index, array in forEach method.
What are we want used there value any one or three so.

Test case - login_ATM

ViGnEsH — Mon, 13 Apr 2026 16:12:47 +0000

April - 13 - 2026

LOGIN TEST in Excel:

Checking Login methods:

USERNAME: CORRECT / PASSWORD: CORRECT
USERNAME: WRONG /PASSWORD: CORRECT
USERNAME: CORRECT / PASSWORD: WRONG
USERNAME: WRONG / PASSWORD: WRONG
USERNAME: WRONG / PASSWORD: WRONG

ATM TEST in Excel:

Checking ATM methods:

Amount: Pass / PIN: PASS
Amount: Wrong / PIN: Pass
Amount: Wrong / PIN: PASS
Amount: Pass / PIN: Wrong
Amount: - / PIN: -
Amount: - / PIN: -

Sofware Developer Life Cycle (SDLC)

ViGnEsH — Mon, 13 Apr 2026 04:46:30 +0000

April-12-2026

Sofware Developer Life Cycle (SDLC)

SDLC is a stand for Sofware developer life cycle ( or sometime System Development Life Cycle)
A Structured, step by step process used by terms.

SDLC Diagram:

Sofware Developer Life Cycle (SDLC) a setps

Requirement Gathering
Planning
Design
Development
Testing
Support& Maintenace

1. Requirement Gathering

Requirement Gathering is (BA) is stand Business Analysis jop role, Business Analysis is gathering in information for client.
(FRS) in stand Function requirement specification, for clint what can create we developed of project.
It clinet finally all business analysis find create (BRS) stand Business requirement specification, check senior all done next step.

2. Planning

Why to do
What to do
when to do
how to do

Planning SDLS is the foundationad first phans the define project scope, goals, risk and resource requirement.
It set a roadmap, cost estimation, scsheduling and resource planning.

3. Design

The stage, the approved requriement and transformed into technicat for project blueprint for implementation.
There are step process in (BRS) structured and project review for client.

4. Development Coding

Developes build the software based for approved design term.

Activities: Coding, code review, view control management.
Output: Source code, executable application.
Key Roles: Frontend, Backend, Full Stack Developers

Who to development Finally find: The are (BRS) File all done find for project.
Development also unit test is basic testing.

4. Testing

Sofware Testing are test developer build a program for check of current run,
It any bug, error loading process very for test.
Find the any bug or error report for developer can fixed and again check testing all find no bug or error go to next stage.

6. Support& Maintenace

The SDLC doesn't end when the software is deployed. The maintenance phase entails the postdeployment work that software teams.
Continual fixes and improvements Updated and optimized code.

Common software development lifecycle models

There are many different software development (SDLC) models:

Waterfall
V-model
Agile
Lean
Iterative
Spiral
Big bang
Rapid application development (RAD)

Choosing the right SDLC model depends on various factors.

JavaScrpit ->Data Types, Variables

ViGnEsH — Fri, 10 Apr 2026 07:48:04 +0000

2026 / April / 09

JavaScript

JavaScript (JS) is a programming language used in primarily for web development.
It is used to create dynamic feature for webpage and website.
It is store information used in variables and rules that guide how to used in interact with a program.
Also JavaScript is a Scripting Languages.
A JavaScript is a programming language designed to to automate excution.
Excuted in one by one or by line by interproter .
It is compline into machine code and we run a code.

Data Types

A JavaScript variable can hold 8 types of data, That are 7 is Primitive Data Types and 1 is non primitive Data type.

Primitive Data type

A JavaScript primitive data types define values for variables can hold, There are 7 is Primitive Data Types

Number
The are represent integer & floating both Ex:12 , 3.4
String
Single Quotes > 'Hello' / Double Quotes "Hello" / Backtick

`Total: ${price+
tax}`                (TBD)

Bigint
Bigint is same number value also more than 10 value you can used.
Boolean
The are represent are one of two value ;true or flase
Undefined
JS Global propreties are undefined values , varible is declaed ans not intilized.

Example:

Null Null is a used can't give value used for null

Example:

Symbol This used to unique symbol like percentage,greater than and lessthan etc.

Non primitive Data type

Object Object is a non-primitive data types in javascript it used to multiple value store data,Created within {} or the new keyword. It is fundamertal as nevarly everything in Javascrpit in object.

Array An array is a non-primitive data types in javascript it used to multiple element under a single name. Created within [] Squard brakets or the new keyword. Ordered list value store in index numbers that start from 0.

Function Function is a non-primitive data types in javascript are also object. It can be assigned to variable, passed used argument to return for function.

Difference Between Primitive and Non Primitive Data Types:

Mutability:
Primitive data types are immutable, meaning their value once assigned can't change value create in new values
Non primitive data types are mutable and is can be change(modified values).

Storage:
Primitive data types are stored by value in stack (FILO) first in last out
Non Primitive data types are store by value in Heap their are refereances in value memory.

Comparison:
Primitive data types are compared by value
Non Primitive data types are compared in data address there is reference

Variables

Javascript variable are sympolic name used a containes to store data types
The are allow in information, such number or text write a code.
variable name _ undersore $ dollar sign allowed.

declared in 4 ways:

    1. automalically is a same variable name allowed in code

     2. var is a same variable name allowed in code but it is used for function data types this function scope.

     3. let provide block-level scoping, their are reassigind a value but redectarable not allowed

reassigind

redectarable

       4. const provide block-level scoping, their are reassigind and redectarable both not allowed.

reassigind and redectarable

referrenced : W3school, ideed, mdn, geeksofgeek...

Basic Array Methods

ViGnEsH — Wed, 08 Apr 2026 11:46:50 +0000

April -08 -2026

Array length

the length proerty return the arrayName.length of array.

Example

Array toString()

toString is used array string or non check,
Number also add in string.

Array at()

The at() method used to index for array elements
The are at(2) 2 element only print.

Array join()

Array join methed is used join add element string.
The join is no change main array.

Array push() and Array pop() : Add and Remove for end element.

Array push() -> push () method is extra element add in last

Array pop() -> pop () method is remove element in last element

Array shift()
Array unshift()

Array shift() and Array unshift() : Add and Remove for end element.

Array shift() -> shift () method is remove element in frist element

Array unshift() -> push () method is extra element add in frist

Array isArray()

Array isArray method is that program array or not check used
that program not array this all array methods no work
add a new element.

Array delete()

delete method remove element but that space empty delete arrayName [0]

Array concat()

Array concat() is join two arrays
used different store for concat.

Array copyWithin()

copyWithin() is index 2,0 is index value repect change.

Array flat()

Array flat() is multiple array store one array.

Array slice()

Slice method is slice piece any index
remove in array

Array splice()

Array splice() add index element .

Array toSpliced()

The difference between the new toSpliced() method and the old splice() method