JavaScript Basics Quiz

• JavaScript is a high-level, interpreted programming language.
• It's primarily used in web development, enabling dynamic behavior on web pages.
• JavaScript is a prototype-based language where objects inherit properties and methods from other objects.
• Its syntax resembles Java but is designed for scripting without needing compilation.
• JavaScript code can be embedded directly within HTML documents using <script> tags.

Core Concepts

• Variables: Used to store data, declared with let, const, or var. Data types include numbers, strings, booleans, arrays, and objects.
• Operators: Used for operations on variables (arithmetic, comparison, logical).
• Control Flow: Statements (if-else, loops, switch) manage program execution based on conditions.
• Functions: Self-contained code blocks, reused using the function keyword or arrow function syntax.
• Objects: Collections of key-value pairs (properties and methods); represent complex data structures.

Data Types

• Numbers: Represent numerical values (integers and floats).
• Strings: Sequences of characters in single or double quotes.
• Booleans: Represent truth values (true or false).
• Arrays: Ordered collections of values (including other arrays or objects).
• Objects: Collections of key-value pairs; keys are strings, values can be various data types.

Programming Constructs

• Conditions (if-else): Execute different code blocks based on conditions.
• Loops (for, while, do-while): Repeat code blocks until a condition is met.
• Functions: Reusable code blocks; accept arguments and return values.
• Error Handling (try-catch): Manages exceptions during execution.

Dynamic Typing

• JavaScript is dynamically typed; variable types are inferred or checked at runtime.

JavaScript Libraries and Frameworks

• JavaScript is frequently used with libraries and frameworks like jQuery, React, Angular, and Node.js. These extend JavaScript's basic functionalities.

Object-Oriented Programming (OOP)

• JavaScript supports OOP concepts but is prototype-based (not class-based like Java or C++). It focuses on prototypes and inheritance.

Working with the DOM

• Document Object Model (DOM) is an API for interacting with HTML documents. JavaScript can access and manipulate HTML elements through the DOM, enabling dynamic updates.

Asynchronous Operations

• JavaScript's single thread can be slow with long operations (like network requests). Asynchronous programming handles these without blocking the main thread using async/await and callbacks.

Modules

• Modern JavaScript uses modules (import and export) for better code organization. It allows projects to be broken down to improve maintainability.

Client-Side vs. Server-Side

• JavaScript is commonly used on the client-side (in web browsers) within HTML pages.
• Node.js enables server-side JavaScript (running on a server).

Event Handling

• JavaScript often responds to user interactions (events). Event handlers are functions triggered by events like button clicks, mouse movements, and key presses.