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.
A string in SQL is a sequence of characters. In practice, it is rarely clean. It has leading and trailing whitespace, inconsistent casing, substrings that need extraction, parts that need concatenation, and lengths that need measuring. SQL provides a set of string functions for these operations, and although the exact names vary slightly between databases,…
Accessibility is not a feature that can be added at the end. It is a property of the markup, the styles, and the interaction, and it must be designed from the start. Tailwind provides a small set of utilities and variants that address the most common accessibility needs: the sr-only and the not-sr-only for the…
An event emitter is a publish-subscribe mechanism: one part of a system announces that something happened, and other parts subscribe to be notified. Node.js has EventEmitter. The browser has addEventListener and CustomEvent. Angular has EventEmitter and signals. Every framework has some version of the pattern. The untyped versions share the same weakness: the event name…
A composable that accepts a value has to decide what it accepts. A plain number, a ref, a computed, or a getter function: all four are reasonable, and all four appear in real code. A composable that only accepts one of them is rigid, and a composable that requires the caller to unwrap is annoying….
Signals and RxJS are the two reactive models in modern Angular, and they are not competing. Signals are for synchronous state — a counter, a filter, a form value — and they are read with () and tracked automatically. RxJS is for asynchronous streams — HTTP, WebSockets, timers, route parameters — and the operators compose…
These transform functions slant or distort elements along the X or Y axis, creating a parallelogram effect. They’re useful for dynamic banners, stylized cards, and geometric layouts. Overview of Functions Function Axis Effect Equivalent skew() X and/or Y Slants both axes skewX() + skewY() skewX() Horizontal Slants left/right skew(angle, 0) skewY() Vertical Slants up/down skew(0,…
Dart’s memory model is built around a single insight: most objects die young. In a typical application, the majority of allocated objects become unreachable almost immediately, while a small minority survive to become long-lived. A garbage collector that treats all objects equally wastes time repeatedly examining the long-lived ones. A collector that exploits the age…
A Docker image is not a single artifact. It is a stack of layers: a base operating system with its package manager, a language runtime with its dependency tree, and the application code itself. Each layer carries its own inventory of packages, and any one of them can contain a known vulnerability. Scanning exists to…
BigInt is a numeric type for arbitrary-precision integers. Where regular JavaScript numbers lose precision past 2^53 – 1, BigInt keeps exact values no matter how large. It’s the tool for cryptography, large IDs, precise timestamps in nanoseconds, and anywhere exact integer math matters. Key point: BigInt and Number are different types. You can’t mix them…
Password hashing is the last line of defense when a database is compromised. The choice of algorithm and its configuration determines how long an attacker must spend to recover each password. Node.js offers three viable paths: the bcrypt npm package, the argon2 npm package, and the built-in crypto.scrypt function. Each has a different operational profile,…