Tutorials covering programming languages, type systems, architecture, tooling, and the patterns used to build software that lasts. Each chapter is standalone, built around real examples and verified facts.
Every component can have its own CSS. Angular scopes those styles to the component’s template so a .title rule in one component doesn’t affect .title elements in another. That scoping is called view encapsulation, and it’s the mechanism that lets you write component CSS without global naming conventions like BEM, without worrying about collisions, and…
These three properties are the foundation of the CSS Box Model. They control the spacing around elements (margin), the spacing inside elements (padding), and the outline of elements (border). Overview of the Three Properties Property Description Where It Applies margin Space outside the border Between the element and its neighbors padding Space inside the border…
A Map is a collection of key-value pairs. Each key is unique, and each key maps to exactly one value. The map is the collection for lookups: given a key, retrieve the value. Where a List is indexed by position and a Set is indexed by membership, a Map is indexed by a key of…
By default, Docker runs every container as the root user (UID 0). This means that if an attacker exploits a vulnerability in your application and manages to break out of the container, they have root-level access on the host machine. Running containers as a non-root user is one of the most effective security measures available,…
Semantic elements are HTML elements that carry meaning about the content they contain. They describe the purpose of the content rather than just its appearance, making web pages more accessible, SEO-friendly, and maintainable. Semantic vs. Non-Semantic Elements Type Description Examples Semantic Elements with meaning that describe content structure <header>, <nav>, <main>, <article>, <section>, <aside>, <footer>,…
A closure is a function that retains access to its lexical scope, even when the function is executed outside of that scope. This means a closure can “remember” and access variables from the environment in which it was created — even after that environment has finished executing. A Quick Look at the Examples a. Closure…
Paths are strings, but not all strings are valid paths on every platform. Windows uses backslashes as separators, Linux and macOS use forward slashes, and the two systems disagree about drive letters, case sensitivity, and reserved characters. The node:path module exists to hide these differences. It provides functions for joining path segments, resolving relative paths…
Version management is the discipline of incrementing a package’s version number in a way that communicates the nature of the change to the consumers who depend on it. The npm version command automates this increment, writing the new version to package.json and package-lock.json, and—when run inside a Git repository—creating a commit and a tag that…
When a state update depends on the previous value, React provides a functional form of the setter that receives the current state as its argument. This is not a stylistic preference; it is the correct way to express the update when the new value is derived from the old one. The direct form — reading…
The aliasing XOR mutability rule is the single most important invariant in Rust’s type system. It states that at any given time, a value may be accessed through either one mutable reference or any number of immutable references, but never both. Every other safety guarantee in the language — the absence of data races, the…