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
JavaScript
Deep Clone Object
Creates a true deep copy of any serialisable object or array — nested objects, arrays, dates (as ISO strings). Uses structuredClone when available (modern browsers/Node 17+) and falls back to JSON round-trip for older environments. Does not handle functions, undefined, or circular references.
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SQL
CASE WHEN — Conditional Values
Inline if/else inside a SELECT, ORDER BY, or aggregation. The Swiss-army knife for converting raw column values into labels or buckets.
SQL
Soft Delete with Partial Index
Set a `deleted_at` timestamp instead of physically removing rows — preserves history and lets you "undelete". Pair with a partial index for fast queries that skip the soft-deleted rows.
PHP
Index Array By Column
Rekey a list of rows by one of their column values, so $byId[42] gives the row with id=42. Equivalent to array_column($rows, null, $key).
TypeScript
Concurrency Limiter (semaphore)
Run an array of async tasks but limit concurrency to N at a time — like p-limit, in 30 lines. Preserves input order in the output array.
Go
select — Multiplex Channel Operations
`select` is like a switch for channels — runs whichever case is ready. Use `default` for non-blocking sends/receives; `case <-time.After(d)` for timeouts.
PHP
Format Money with Currency
Format an amount of cents as a localized currency string using NumberFormatter from intl. Falls back to a basic sprintf if intl isn't available.
Rust
Format Strings (println! / write!)
Rust's format macros take an inline format string with `{}` placeholders. Named arguments, alignment, precision, debug formatting — all in the format spec.
Rust
Builder Pattern with Method Chaining
Construct complex objects step-by-step with `self`-returning methods. Type-state can enforce required vs. optional fields at compile time — but the simple version is plenty for most cases.
PHP
cURL Multipart File Upload
Upload one or more files via multipart/form-data using cURL's CURLFile abstraction. No manual boundary or body construction needed.
Go
Table-Driven Tests with t.Run
A table of test cases looped through `t.Run` gives every case its own name in the output, makes adding new cases trivial, and lets you run individual cases with `-run TestX/case_name`.
Go
Pointers — When and Why
Use pointers when you want to mutate the callee's value, share a large struct without copying, or distinguish "no value" via nil. Go has no pointer arithmetic — much safer than C.
SQL
RETURNING — Get Back What You Wrote
PostgreSQL `RETURNING *` returns the rows affected by an INSERT/UPDATE/DELETE — no separate SELECT round-trip needed. SQL Server has `OUTPUT`; MySQL added `RETURNING` in MariaDB and 8.0.31+.
PHP
Number to Ordinal (1st, 2nd, 3rd)
Convert an integer to its English ordinal form ("1st", "2nd", "3rd", "11th", "22nd", "103rd"). Pure rule-based; no library needed.
PHP
Safe Path Join
Concatenate path segments and produce a normalized canonical path that resists "../" escape attempts. Throws if the result would land outside the given base directory.
PHP
Pluck Column From Array of Rows
Extract a single column from a list of associative arrays into a flat list. Common transformation for SELECT results — equivalent to array_column with optional indexing key.
Rust
Option Combinators (no unwrap!)
`Option<T>` has a rich combinator API that lets you avoid both `unwrap()` and the verbose `match`. Chain `map`, `and_then`, `unwrap_or`, `or_else` to compose fallible operations.