Tags
#php
#kotlin
#bash
#go
#sql
#rust
#typescript
#html
#java
#python
#files
#utils
#strings
#http
#concurrency
#async
#json
#arrays
#security
#types
#crypto
#database
#dates
#format
Python
Producer / Consumer Queue (threading)
Classic producer / multi-consumer pattern using queue.Queue. Producers put work onto the queue; consumers pull and process; a sentinel value signals shutdown.
@admin
Java
Files.walk — Recursive Tree Traversal
`Files.walk` returns a lazy Stream over every entry under a path. Filter with stream operations; remember to close the stream (or use try-with-resources).
JavaScript
LocalStorage with Expiry
Extends localStorage with TTL (time-to-live) support. setItem stores a value alongside an expiry timestamp. getItem returns null and removes the key if the TTL has elapsed. Useful for caching API responses client-side, storing ephemeral UI state, and implementing remember-me tokens without a backend session.
PHP
Secure Session Bootstrap
Start a session with all the security flags you should always set: HttpOnly, SameSite=Strict, Secure on HTTPS, custom name, and an idle-timeout regeneration.
TypeScript
Sum / Mean / Median (numeric arrays)
The descriptive-stat trio for number[]. Median sorts a copy so the input is left alone. Empty input returns 0 / 0 / 0 rather than NaN — opinionated, but predictable.
HTML
Select with Optgroup
`<optgroup label="...">` visually groups options inside a `<select>`. Renders as a non-selectable header in every browser; screen readers announce the group as context.
PHP
Random Readable Token
Generate a short, human-readable random token using an alphabet that omits look-alike characters (0/O, 1/l/I). Useful for invite codes, short-lived signin tokens, password reset codes — anything a human might type.
Bash
Uppercase / Lowercase / Title Case
Bash 4+ has built-in case conversion via parameter expansion. No need for `tr` or `awk` for most cases.
Java
Collectors.toMap with Merge Function
`toMap` builds a `Map<K, V>` from a stream. The 3-arg form takes a merge function for handling duplicate keys — without it, duplicates throw IllegalStateException.
Kotlin
JDBC with use { } — Auto-Close Connections
Plain JDBC is fine for simple cases. Wrap connections / statements / result sets in `use { }` for guaranteed cleanup even on exceptions.
Bash
Check URL Returns 200
Quick health-check helper: returns 0 if a URL responds with a 2xx status, non-zero otherwise. Use in pre-deploy smoke tests.
Go
time.Format — The Reference Time
Go's time formatting uses a reference date instead of strftime tokens: `Mon Jan 2 15:04:05 MST 2006` (which is 01/02 03:04:05PM '06 -0700, or 1/2/3/4/5/6/7 — mnemonic). Strange at first, instantly memorable.
PHP
Bulk INSERT in a Single Statement
Insert a list of rows in one round trip by building a multi-VALUES statement with placeholders. Orders-of-magnitude faster than looping single INSERTs.
Kotlin
Compose State Hoisting
Lift state UP to where it's needed. A composable becomes "stateless" (taking `value` + `onValueChange`) which makes it reusable and testable. The Compose mantra.
PHP
Haversine Distance Between Two Coordinates
Compute the great-circle distance between two latitude/longitude points using the haversine formula. Returns kilometers; multiply by 0.621 for miles. Useful for "stores near me" features.
Go
SHA-256 Hash of File or String
`crypto/sha256` is the canonical hash. Use the streaming `Hash` interface for files — never load multi-GB content into memory just to hash it.
Java
Stream.generate / iterate — Infinite Streams
Build streams from a seed + a function. `generate(supplier)` calls the supplier each time; `iterate(seed, next)` applies a unary op. Always pair with `limit` to bound them.