Expand/Collapse Widgets

JavaScript is a versatile, high-level programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS.

Key Features:

• Dynamic typing and first-class functions
• Prototype-based object-orientation
• Multi-paradigm (event-driven, functional, imperative)
• Runs in browsers and on servers (Node.js)

JavaScript enables interactive web pages and is an essential part of web applications. The vast majority of websites use it for client-side page behavior.

Flexbox is a one-dimensional layout method for arranging items in rows or columns. Items flex to fill additional space or shrink to fit into smaller spaces.

Main Concepts:

• Flex Container: The parent element with display: flex
• Flex Items: The direct children of a flex container
• Main Axis: The primary axis along which flex items are laid out
• Cross Axis: The axis perpendicular to the main axis

Common Properties:

justify-content, align-items, flex-direction, flex-wrap, and flex-grow are among the most commonly used flexbox properties.

Responsive web design is an approach to web development that makes web pages render well on a variety of devices and window or screen sizes.

Core Principles:

• Fluid grids that use relative units like percentages
• Flexible images that scale within their containing elements
• Media queries to apply different styles for different screen sizes
• Mobile-first approach for better performance

By using responsive design techniques, developers can create websites that provide an optimal viewing experience across a wide range of devices, from desktop computers to mobile phones.

Web accessibility means that websites, tools, and technologies are designed and developed so that people with disabilities can use them.

Why It Matters:

• Ensures equal access and equal opportunity to people with disabilities
• Improves usability for all users
• Often required by law in many jurisdictions
• Expands market reach and audience

Best Practices:

Use semantic HTML, provide text alternatives for images, ensure keyboard navigation, maintain proper color contrast, and use ARIA attributes when necessary.

ECMAScript 6 (ES6) and later versions introduced many powerful features that make JavaScript more expressive and easier to work with.

Popular Features:

• Arrow Functions: Shorter syntax for function expressions
• Template Literals: String interpolation and multi-line strings
• Destructuring: Extract values from arrays or objects
• Promises & Async/Await: Better handling of asynchronous operations
• Modules: Import and export functionality between files
• Spread Operator: Expand iterables in places where arguments are expected

These features have significantly improved code readability and developer productivity.