Week 6 — HTML, CSS, JavaScript, TypeScript & HTTP

[HTTP] What is HTTP?

Hypertext Transfer Protocol is an application-layer request-response protocol used to transfer web resources and API data.

[HTTP] What are GET, POST, PUT, PATCH and DELETE used for?

GET retrieves, POST submits or creates, PUT replaces, PATCH partially updates, and DELETE removes resources.

[HTTP] What is the difference between 200, 201, 400, 401, 403, 404 and 500?

Success, created, bad request, unauthenticated, forbidden, not found and internal server error respectively.

[HTTP] What is the difference between HTTP and HTTPS?

HTTPS carries HTTP over TLS, providing encryption, integrity and server authentication.

[HTTP] What is an HTTP header?

Metadata accompanying requests or responses, such as Content-Type or Authorization.

[HTTP] What is REST?

An architectural style using resources, representations, standard HTTP semantics and stateless interactions.

[HTML Fundamentals] What is HTML?

HyperText Markup Language structures web content using elements and attributes.

[HTML Fundamentals] What is semantic HTML?

Elements such as header, nav, main and article express content meaning and improve accessibility.

[HTML Fundamentals] What is the DOM?

The Document Object Model is a tree representation of a document that scripts can read and modify.

[HTML Fundamentals] What is the difference between id and class?

id identifies a unique element in a document; class groups elements for shared styles or behavior.

[HTML Fundamentals] Why is accessibility important?

Semantic markup, labels and keyboard support help people and assistive technologies use websites.

[HTML Forms] What is an HTML form?

A form collects user input and can submit it to a server using a specified action and method.

[HTML Forms] What is the difference between GET and POST forms?

GET sends form values in the URL query string; POST usually sends them in the request body.

[HTML Forms] Why associate a label with an input?

Labels improve accessibility and let users focus an input by clicking its label.

[HTML Forms] What is client-side validation?

Browser-side checks such as required and pattern provide quick feedback but must be repeated server-side.

[HTML Forms] What is the purpose of input name?

It identifies the key used when form data is submitted.

[CSS] What is CSS?

Cascading Style Sheets controls the presentation, layout and visual styling of HTML.

[CSS] What is CSS specificity?

A priority system used with cascade rules to decide which conflicting declaration applies.

[CSS] What is the CSS box model?

Content, padding, border and margin determine how an element occupies space.

[CSS] What is Flexbox?

A one-dimensional layout system for aligning and distributing items along a row or column.

[CSS] What is CSS Grid?

A two-dimensional layout system for arranging items into rows and columns.

[CSS] What is responsive design?

A layout approach that adapts to screen sizes using flexible units, media queries and responsive patterns.

[CSS] What is the difference between block and inline elements?

Block boxes normally begin on new lines and fill available width; inline boxes flow with surrounding text.

[JavaScript Fundamentals] What is the difference between var, let and const?

var is function-scoped; let and const are block-scoped; const prevents reassignment of its binding.

[JavaScript Fundamentals] What is a closure?

A function that retains access to variables from its lexical environment after the outer function returns.

[JavaScript Fundamentals] What is the difference between == and ===?

== permits type coercion during comparison; === compares without coercion.

[JavaScript Fundamentals] What is a Promise?

An object representing eventual completion or failure of an asynchronous operation.

[JavaScript Fundamentals] What does async/await do?

It provides syntax for working with Promises in a more sequential-looking style.

[JavaScript Fundamentals] What is the event loop?

A mechanism that coordinates the call stack and queued tasks to run asynchronous callbacks.

[JavaScript Fundamentals] What is an arrow function?

A concise function syntax with lexical this binding.

[JavaScript DOM] How do you select a DOM element?

Use methods such as document.querySelector or getElementById.

[JavaScript DOM] What is an event listener?

A callback registered for an event such as click, input or submit.

[JavaScript DOM] What is event bubbling?

An event propagates from its target upward through ancestor elements unless propagation is stopped.

[JavaScript DOM] What is event delegation?

Attach a listener to an ancestor and handle events from matching descendants, reducing listener duplication.

[JavaScript DOM] What is the difference between textContent and innerHTML?

textContent handles plain text; innerHTML parses markup and can introduce injection risks with untrusted input.

[JavaScript HTTP] What does fetch do?

The browser fetch API makes network requests and returns a Promise for a Response.

[JavaScript HTTP] How do you send JSON using fetch?

Set method and Content-Type, serialize the body with JSON.stringify, and parse responses with response.json().

[JavaScript HTTP] What is CORS?

A browser security mechanism controlling whether scripts can read responses from another origin based on server headers.

[JavaScript HTTP] What is JSON?

A text data format using objects, arrays, strings, numbers, booleans and null.

[JavaScript HTTP] How should failed HTTP responses be handled with fetch?

Check response.ok or status because fetch generally does not reject solely for HTTP 4xx or 5xx.

[TypeScript Introduction] What is TypeScript?

A typed superset of JavaScript that adds static type checking and compiles to JavaScript.

[TypeScript Introduction] What is the difference between interface and type alias?

Both describe types; interfaces support declaration merging, while type aliases also represent unions and other type expressions.

[TypeScript Introduction] What is a union type?

A type allowing a value to be one of several alternatives, such as string | number.

[TypeScript Introduction] What are generics?

Type parameters that make functions and classes reusable while preserving type information.

[TypeScript Introduction] What is type inference?

TypeScript derives a type from context without requiring an explicit annotation.

[TypeScript Basics] What is the difference between any and unknown?

any disables most type checking; unknown requires narrowing before using a value.

[TypeScript Basics] What is optional chaining?

The ?. operator safely accesses properties or methods when an intermediate value may be null or undefined.

[TypeScript Basics] What is a TypeScript enum?

A named collection of related constants; union literal types are often an alternative.

[TypeScript Basics] What is an optional property?

A property marked with ? that may be absent or undefined.

[TypeScript Basics] What is type narrowing?

Refining a union type using checks such as typeof, instanceof or discriminated unions.

[TypeScript Configuration] What is tsconfig.json?

A configuration file defining TypeScript compiler options and included project files.

[TypeScript Configuration] What does strict mode do?

It enables a collection of stricter type-checking options to catch errors earlier.

[TypeScript Configuration] What is target in tsconfig?

It selects the JavaScript language version emitted by the compiler.

[TypeScript Configuration] What is module in tsconfig?

It specifies the emitted module system or module transformation behavior.

[TypeScript Configuration] What does noEmit do?

It type-checks without generating JavaScript output.

[Wireframes] What is a wireframe?

A low-fidelity representation of a screen's structure, content and user interactions before visual polish.

[Wireframes] How does a wireframe differ from a prototype?

A wireframe emphasizes layout; a prototype simulates user flows and interactions.

[Wireframes] Why create wireframes?

They help validate requirements and usability before expensive implementation.

[Wireframes] What is a user flow?

A sequence of screens and actions a user follows to complete a goal.