javascript
Deep equality in JavaScript is trickier than it looks: JSON.stringify fails when key order differs. Compare the real options: the deep-equal package, writing your own recursive check, lodash isEqual, and Node's built-in assert.deepStrictEqual.
typescript
TypeScript's unknown vs any: both bypass strict typing, but unknown forces you to narrow a value before using it, keeping the safety any throws away. Examples show how each behaves and why unknown is the safer default for untyped data.
typescript
Simplifying complicated TypeScript with the KISS principle: refactoring examples show when explicit types improve a simple function and when clever type gymnastics make code harder to review, test, and maintain.
TypeScript switch statements can be more than a chain of cases: wrap the switch in a function for cleaner returns, or swap it for an object map for flat, readable branching. Each technique comes with code samples, pros, and cons so you can pick the right one.
The Record utility type in TypeScript builds object types with fixed keys and value types. A worked example shows Record<Keys, Type> with union keys: restricting IDs to chosen literals and mixing User and AdminUser values, so the compiler flags missing or extra entries.
TypeScript function generators can pause and resume execution, returning values one at a time instead of all at once. What generators are, how yield works in a simple example, and a practical number sum generator that shows where they beat regular functions.
Infinite scroll in React gets much easier with react-query: the useInfiniteQuery hook fetches posts page by page, cancels stale requests with AbortSignal, and exposes fetchNextPage for loading more. A complete typed example wrapped in a reusable usePosts hook.
TypeScript types with many optional fields need comments to explain what goes together. Discriminated unions fix that: split a Task type into per-status variants so invalid combinations fail to compile and the type documents itself. Before and after code included.
Generic types in TypeScript let one function, class, or interface work safely with many data types. What generics are, how a type parameter beats hardcoding a concrete entity type in a validation helper, and honest pros and cons before you use them everywhere.
TypeScript enums generate extra JavaScript at compile time and numeric enums are not even type-safe. Why enums can hurt bundle size and correctness, and two safer alternatives: assigning explicit string values or replacing enums with plain objects.