What are JavaScript modules? How do you export and import them?

JavaScript modules are a way to organize and encapsulate code into reusable units. They allow you to break down your codebase into smaller, self-contained modules, each responsible for a specific functionality. Modules improve code maintainability, reusability, and enable better collaboration among developers. JavaScript modules follow the ES modules (ESM) specification, which is supported by modern … Read more

How can you convert a string to a number in JavaScript?

In JavaScript, there are several methods to convert a string to a number. Here are some commonly used techniques: parseInt() function: The parseInt() function is used to parse a string and convert it to an integer. It takes two arguments: the string to be converted and an optional radix (base) value. Example: const stringNum = … Read more

Explain the concept of the event loop in JavaScript.

The event loop is a critical component of JavaScript’s concurrency model. It manages the execution of asynchronous operations and ensures that JavaScript remains responsive even while performing time-consuming tasks. Understanding the event loop is crucial for writing efficient and responsive JavaScript code. JavaScript is single-threaded, meaning it can only execute one task at a time. … Read more

What is the purpose of the map() method in JavaScript?

The map() method in JavaScript is a powerful array method that allows you to transform each element of an array and create a new array with the results. It is used to iterate over an array and perform a specified operation on each element, returning a new array of the same length. The syntax for … Read more

How do you handle errors in JavaScript?

Handling errors in JavaScript is crucial for writing robust and reliable code. There are several techniques and mechanisms available to handle errors effectively. Let’s explore some of the common approaches: Try…Catch Statement: The try…catch statement allows you to catch and handle exceptions that occur within a specific block of code. The try block contains the … Read more

What are arrow functions in JavaScript?

Arrow functions, introduced in ECMAScript 6 (ES6), are a concise syntax for writing function expressions in JavaScript. They provide a more compact and expressive way to define functions compared to traditional function declarations or function expressions. Here’s the syntax for an arrow function: const functionName = (parameters) => {   // Function body   return value; }; … Read more

Explain the concept of callback functions

In JavaScript, a callback function is a function that is passed as an argument to another function and is intended to be invoked at a later time or after a certain event occurs. Callback functions are a fundamental concept in JavaScript and are widely used for asynchronous operations, event handling, and functional programming. The key … Read more

How can you check if a variable is an array in JavaScript?

In JavaScript, you can check if a variable is an array using several methods. Here are four commonly used approaches: Array.isArray(): The Array.isArray() method is the recommended and most reliable way to check if a variable is an array. It returns true if the provided value is an array; otherwise, it returns false. Example: const … Read more

What is the purpose of the bind() method in JavaScript?

In JavaScript, the bind() method is used to create a new function with a specific this value and, optionally, initial arguments. It allows you to explicitly set the execution context for a function, regardless of how it is called. The primary purpose of the bind() method is to ensure that a function is permanently bound … Read more

Explain the concept of event bubbling and event capturing

Event bubbling and event capturing are two mechanisms used in the event propagation phase in the Document Object Model (DOM) in JavaScript. They determine the order in which event handlers are executed when an event occurs on a nested element within a parent element. Event Bubbling: Event bubbling is the default behavior in which an … Read more