Preamkumar Revathi’s Post

JavaScript Interview Series – Day 10 Let’s understand What is Lexical Scope in JavaScript. Lexical scope means that a function can access variables based on where it is defined in the code, not where it is executed. In simple terms, inner functions can access variables from their outer functions. #JavaScript #NodeJS #WebDevelopment #Programming #SoftwareEngineering #InterviewPreparation

JavaScript Interview Series – Day 7 Let’s understand What is Error Handling in Promises? In JavaScript, errors in promises can be handled using .catch() or try...catch with async/await. This helps prevent application crashes and makes debugging easier. #JavaScript #NodeJS #WebDevelopment #Programming #SoftwareEngineering #InterviewPreparation

JavaScript Interview Series – Day 15 Let’s understand What is == vs === in JavaScript. Both are used for comparison, but they behave differently. 🔎 Key Difference • == → compares after type conversion • === → compares value + type (strict) #JavaScript #NodeJS #WebDevelopment #Programming #SoftwareEngineering #InterviewPreparation

JavaScript Interview Series – Day 13 Let’s understand call(), apply(), and bind() in JavaScript. These methods are used to control the value of this inside a function. 🔎 Key Difference • call() → arguments passed one by one • apply() → arguments passed as array • bind() → returns a new function #JavaScript #NodeJS #WebDevelopment #Programming #SoftwareEngineering #InterviewPreparation

JavaScript Interview Series – Day 11 Let’s understand What is Hoisting in JavaScript. Hoisting is JavaScript’s default behavior of moving variable and function declarations to the top of their scope during the compilation phase. However, only declarations are hoisted not initializations. #JavaScript #NodeJS #WebDevelopment #Programming #SoftwareEngineering #InterviewPreparation

JavaScript Interview Series – Day 8 Let’s understand How setTimeout works internally in JavaScript. Even though setTimeout looks simple, it works using the Event Loop mechanism. When setTimeout is called, it is handled by Web APIs, and after the timer completes, the callback is moved to the Callback Queue. The Event Loop pushes it to the Call Stack only when it becomes empty. #JavaScript #NodeJS #WebDevelopment #Programming #SoftwareEngineering #InterviewPreparation

JavaScript Interview Series – Day 3 Let’s understand What is Async/Await in JavaScript. async/await is a modern way to handle asynchronous operations. It is built on top of promises and makes async code look like synchronous code. This improves readability and avoids complex .then() chaining. #JavaScript #NodeJS #WebDevelopment #Programming #SoftwareEngineering #InterviewPreparation

JavaScript Interview Series – Day 4 Let’s understand Promise vs Async/Await in JavaScript. Both are used to handle asynchronous operations, but they differ in syntax and readability. Promise uses .then() and .catch() chaining, while async/await provides a cleaner, synchronous-like structure. #JavaScript #NodeJS #WebDevelopment #Programming #SoftwareEngineering #InterviewPreparation

JavaScript Interview Series – Day 16 Let’s understand null vs undefined in JavaScript. Both represent absence of value, but they are used differently. 🔎 Key Difference • undefined → default value by JavaScript • null → assigned by developer 🔥 Key Point undefined = value not assigned null = value intentionally empty #JavaScript #NodeJS #WebDevelopment #Programming #SoftwareEngineering #InterviewPreparation

JavaScript Interview Series – Day 14 Let’s understand What is Prototype in JavaScript. In JavaScript, every object has a hidden property called [[Prototype]] which links to another object. This is called the prototype chain. It allows objects to inherit properties and methods from other objects. 🔎 Key Concept • Objects inherit from other objects • Prototype enables code reuse • JavaScript uses prototype-based inheritance #JavaScript #NodeJS #WebDevelopment #Programming #SoftwareEngineering #InterviewPreparation