Event handling in React is how you capture and respond to user interactions such as clicks, typing, mouse movements, form submissions, and more. React handles events in a synthetic event system, which wraps the browser's native events to provide consistent behavior across different browsers. Here’s a clear breakdown: Key Points About Event Handling in…
1. What is State? In React, state is a way to store data that can change over time and affect what’s rendered on the screen. Think of it as a “memory” for your component. When state changes, React automatically re-renders the component with the new value. 2. What is useState? useState is a React…
In React, props (short for properties) are a way to pass data from a parent component to a child component. They make components reusable and dynamic. Here’s a breakdown with an example: 🔹 Basic Example of Props // Child Component function Greeting(props) { return <h1>Hello, {props.name}!</h1>; } // Parent Component export default function App()…
JSX stands for JavaScript XML.It’s a syntax extension for JavaScript that looks like HTML but is used in React to describe what the UI should look like. JSX makes it easier to write and understand the structure of React components. Key Points about JSX: Looks like HTML but isn’t HTML – It gets compiled…
A React CLI usually refers to the tool used to quickly bootstrap and manage React projects. The most common ones are: Create React App (CRA) → traditional way, but less used now. Vite → modern, fast, and lightweight (widely used now). Next.js CLI → for full-stack React apps. 🚀 Setting up a React Project…
In Angular, form validation ensures that user input meets defined requirements before being processed. Angular provides two main approaches for building and validating forms: 🔹 1. Types of Forms in Angular Template-driven forms Simpler, suitable for small forms. Validation is declared directly in the template using directives. Uses FormsModule. Reactive forms More scalable and…
Reactive forms are model-driven: you define the form structure and validation logic in your TypeScript code, then bind it to the template. They are more powerful and scalable than template-driven forms. 1️⃣ Import ReactiveFormsModule In app.module.ts: import { NgModule } from '@angular/core'; import { BrowserModule } from '@angular/platform-browser'; import { ReactiveFormsModule } from '@angular/forms';…
Template-driven forms are simpler and rely heavily on Angular directives in the template rather than creating a form model in the TypeScript component. They are suitable for simple forms. 1️⃣ Import FormsModule First, you need to import FormsModule in your module (app.module.ts): import { NgModule } from '@angular/core'; import { BrowserModule } from '@angular/platform-browser';…
1. Observable An Observable is a stream of data that you can subscribe to. It’s cold by default, meaning it doesn’t emit values until someone subscribes. Example: import { Observable } from 'rxjs'; const observable = new Observable<number>((subscriber) => { subscriber.next(1); subscriber.next(2); subscriber.next(3); subscriber.complete(); // completes the stream }); observable.subscribe({ next: (value) => console.log('Received:',…
RxJS (Reactive Extensions for JavaScript) uses Observables to handle asynchronous data streams, and operators help you manipulate these streams. Operators are usually divided into creation, transformation, filtering, combination, and utility operators. Here’s a detailed overview: 1. Creation Operators These operators are used to create Observables. of Emits a sequence of values you provide. import…