DELOWAR HOSSAIN

English is Easy!!

আজ থেকেই আপনার ভাষা শেখার যাত্রা শুরু করুন। আপনি যদি নতুন হন অথবা আপনার দক্ষতা বাড়াতে চান, আমাদের Interactive Lessons আপনাকে নিয়ে যাবে অন্য একটি Level এ

Frequently Asked Questions

1. what is the difference between var, let, and const?

- var: Function-scoped, can be redeclared & reassigned, hoisted with `undefined`.
- let: Block-scoped, cannot be redeclared, hoisted but not initialized.
- const: Block-scoped, cannot be reassigned, must be initialized at declaration.

2. What is the difference between map(), forEach(), and filter()?

- map(): Returns a new array with modified values.
- forEach(): Loops through elements but does not return a new array.
- filter(): Returns a new array with elements that satisfy a condition.

3. Explain arrow functions and how they are different from regular functions?

Arrow functions (`=>`) provide a shorter syntax and do not bind `this`.
Differences:
- No own `this` (inherits from parent scope).
- Cannot be used as constructors.
- No `arguments` object (use rest parameters instead).

4. How do JavaScript Promises work?

A Promise represents a future value that can be `fulfilled`, `rejected`, or `pending`.
- Use `.then()` for success handling.
- Use `.catch()` for error handling.
- Use `async/await` for cleaner asynchronous code.

5. How do closures work in JavaScript?

A closure allows a function to remember variables from its parent scope, even after the parent function has executed. Example:

    
        function outer() {
            let count = 0;
            return function inner() {
                count++;
                console.log(count);
            };
        }
        const counter = outer();
        counter(); // 1
        counter(); // 2

English is Easy!!

Let's Learn Vocabularies

একটি Lesson Select করুন।

Frequently Asked Questions