DEV Community: Ajay

About a Programming Paradigm

Ajay — Sun, 25 Oct 2026 07:42:58 +0000

It is the idea, model or fundamental style of solving problem using programming language,It porvides the structured approach or set of principle that make the programs to design and implement,

Different programing language uses different paradigm techniques to solve the problem.
A programming language used one or more paradigm , to make an best approach for the project requirement.

There Different Types of paradigm approach,

1. Imperative Paradigm

It will focus on step by step instrcution to machine , should complete the task , we can specify the operation and work flow of control during the execution

let num = [1,2 ,3 ,4 ,5];
let total = 0;

for(i =0;i<num.length;i++){
     total = total + num[i];
}

console.log(total);

- Procedural Programming paradigm
It will ogranizes a program into the procedural and function which will perform the specify task

- Object Oriented programming
object oriented program will ogranizes the program into class and objected structure, the object will contain data and methods

- Parallel Processing Approach
It will perform the multiple operation at the same time , usually it use multiple cpu core and computer resources.will increase the efficieny of the program

2. Declarative Paradigm

It will focus on what the result we want rather than the specifying every steo required.

let numbers = [10, 20, 30, 40];

console.log(sum(numbers));

Output:

100

- logic Programming Paradigm
Logic programming expresses problems through facts, rules and logical relationships. A system uses those rules to determine answers.

- Functional Programming
Functional programming builds programs using functions that transform inputs into outputs. It often emphasizes pure functions, immutable data and avoiding unnecessary side effects.

- Database Processing Approach
Database processing often uses declarative queries to describe the data we want to retrieve or modify in the database.

Error may Occur in simple " Hello world " Program in Java

Ajay — Fri, 23 Oct 2026 12:28:58 +0000

This the simple hello world program in java ,In this we can make a simple sytnax error and finding some of it,

1)If we can remove an class in first line ,

2)If we reomve an file name(Home)

here the expected should be , which an file name

3)If we remove static in second line

the java complier is creating the byte code but the output is error.

4)If we remove void ,

Here the method declaration error which denoting the void is required
5)If we remove main

here the means main , beacuse Main is the method name the JVM looks for as the entry point of the program.

6)if we remove String[]args,

the java complier is creating a byte code but output have not be successful

7) If we removed System,

8)If we removed System. ,

9) If we remove out or Out in frist letter in case sensitive

this for out removed ,

this for Out in first letter case Sensitive,

10)If we removed println ,

here the < identifer> required as println

11) If there is no content in java file eventhough extension is .java

UseEffect-Hook

Ajay — Thu, 01 Oct 2026 09:40:57 +0000

1. Run Only Once

Print "Component Mounted" only once when page loads.

-How will you write useEffect?

-What should be in dependency array? Why?

The dependency array should like an empty array "[ ]" because the empty array run the useEffect when the components is mounted.

2. Run on Every Render

Print "Rendered" on every render.

- How will you write useEffect?

- What happens if dependency array is not provided?

If the dependency array is not provided, useEffect runs after every render of the component. Therefore, when a state change causes the component to re-render, the useEffect runs again.

3. Run When State Changes

const [count, setCount] = useState(0);

Log "Count changed" only when count changes.

- What should dependency array contain?

The dependency array should contain the state variables that the useEffect should watch for changes.

- What happens if it is empty [ ]?

If we give an empty [ ] ,The useEffect will run only once when the first time component is mounted.

4. Two States, One Effect

const [count, setCount] = useState(0);

const [name, setName] = useState("");

Run effect when count OR name changes.

- How will dependency array look?

The dependancy array look like an both count and name in the single array "[count , name] ".

- What if only count is added?

If only count is added to the dependency array, the useEffect watches only for changes in count. When count changes, the useEffect runs again. If name changes, this useEffect does not run because name is not included in the dependency array.

5. Derived Logic

Show "Even Number" whenever count becomes even.

- Should this logic be inside render or useEffect? Why?

The logic is inside useEffect because we want to perform the console log when count changes. The [count] dependency makes the UseEffect to run whenever count changes, and the if condition checks whether the new count is even.

6. Infinite Loop Trap

useEffect(() => {

setCount(count + 1);

}, [count]);

- What will happen?

In this the dependancy array has[count],The UseEffect will runs whenever the count variable is changed because the useEffect itself incrementing the change in state(setCount(count+1) ,Therefore the continous loop has created.

- Why does this cause infinite re-render?

The useEffect runs whenever count changes because count is in the dependency array. Inside the useEffect, setCount(count + 1) changes the count state. This causes the component to re-render. Since count changed, the useEffect runs again and changes count again. This process repeats continuously, causing an infinite loop.

7. Fix the Infinite Loop

- How can you increment count only once using useEffect?

If we give an empty dependency array "[ ]" means it runs only once and inside the useEffect the setCount(count +1) changes the state therefore the useEffect run and the initial value is increment only once.

8. Document Title Sync

useEffect(() => {

document.title = count;

}, [?]);

- What should go inside ? Why?

The dependency array should contain [count] because the useEffect runs every state of change in count and inside the useEffect the document.title were mounted to count there the result of the count is displayed in the document.title .

9. Cleanup Basic

useEffect(() => {

window.addEventListener("click", handleClick);

});

- What problem may happen?

The event listener is added after every render, so handleClick may be called multiple times for a single click.

- How to fix properly?

- When does cleanup run?

Cleanup runs when the component is unmounted.

10. API Call on Mount

Fetch users when component loads.

- Why do we use [ ]?

We use an empty dependency array [ ] because we want the API call to run only once after the component's initial render.

- What happens if we remove [ ]?

If we remove [ ], the useEffect runs after every render. Therefore, the API call will be made after every render, which can cause unnecessary API requests and may lead to performance problems.