What is React.js ?

• to JSX using curly braces {}.
• Compilation Requirement: Browsers cannot read JSX natively; tools like Babel transpile it back to native JavaScript. [1, 2, 3, 4, 5]

jsx

const user = "Alex";
const element = <h1>Hello, {user}!</h1>; // Valid JSX syntax

Unidirectional Data Flow

• One-Way Streams: Data always moves downwards from parent components to child components.
• Predictable Tracking: This hierarchy simplifies debugging, as tracking a bug's origin requires looking upwards. [1, 2, 3, 4, 5]

Props vs. State

• Props (Properties): Immutable configurations passed down into a child component from its parent.
• State: Local, mutable data held within a single component that controls its behavior and memory. [1, 2, 3, , ]