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
Chunk Array
Splits an array into smaller arrays (chunks) of a specified size. The last chunk may be smaller if the array length is not evenly divisible. Useful for batch processing, pagination, rendering large lists in chunks, and rate-limited API calls.
@admin
HTML
Datalist — Autocomplete Suggestions
`<datalist>` attaches type-ahead suggestions to any text input. The user can still type something custom — it's suggestions, not a hard constraint.
Go
http.Client with Timeout
`http.DefaultClient` has no timeout — a hung server can hang your whole program forever. ALWAYS use a custom client with an explicit timeout for outbound requests.
HTML
Login Form (with autocomplete hints)
A complete login form with the autocomplete attributes that browsers + password managers depend on. Missing these causes 1Password, Bitwarden, and Chrome to mis-detect the form.
SQL
Window Function vs N+1 Query
Don't fetch a list, then loop in code to count each parent's children. Use a window function or a single GROUP BY — turn 1,001 queries into 1.
SQL
Pattern Matching — LIKE / ILIKE / SIMILAR
`LIKE` uses `%` (any string) and `_` (single char). PostgreSQL `ILIKE` is case-insensitive. For real regex, reach for `SIMILAR TO` (POSIX) or `~` (PostgreSQL).
HTML
Registration Form (new-password + email-verify)
`autocomplete="new-password"` tells password managers to OFFER a generated password instead of filling an existing one. `autocomplete="email"` and `inputmode="email"` give phones the right keyboard.
SQL
TRUNCATE vs DELETE
`DELETE` is logged per-row and respects triggers; `TRUNCATE` deallocates whole pages and resets the table to empty. `TRUNCATE` is much faster on large tables but has caveats (no WHERE, can't be rolled back in some DBs).
SQL
FULL OUTER JOIN / CROSS JOIN
`FULL OUTER` keeps unmatched rows from BOTH sides. `CROSS JOIN` is the Cartesian product — every row of A paired with every row of B. Rare but useful for date-spine and matrix generation.
Go
Functional Options Pattern
Replace giant config structs with a variadic list of `Option` functions. Lets you add optional parameters later without breaking existing callers. The standard Go API design for constructors.
Bash
Check If Array Contains Element
A pure-bash membership test using `=~` or by iterating. Both are useful — pick by readability vs. speed.
Bash
Slice Bash Array
Bash supports Python-like array slicing via ${arr[@]:offset:length}. Lets you take/skip elements without external tools.
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.
SQL
Array Columns (PostgreSQL)
Native array columns avoid an extra join for "small list of things per row" patterns — tags, categories, allowed_roles. Combine with GIN index for fast `@>` / `&&` operators.
HTML
Form Validation Attributes
Built-in client-side validation: `required`, `pattern`, `minlength`/`maxlength`, `min`/`max`. The browser blocks submission and shows a native error if anything fails. Always validate on the server too.
SQL
EXPLAIN / EXPLAIN ANALYZE
`EXPLAIN` shows the query plan; `EXPLAIN ANALYZE` actually runs it and shows real timings. The first tool when a query is slow — look for sequential scans on big tables.
SQL
MERGE — One Statement for INSERT + UPDATE + DELETE
`MERGE` (standard SQL, PostgreSQL 15+, SQL Server, Oracle) is a single statement that combines INSERT/UPDATE/DELETE driven by joining a source against a target. Heavy artillery for reconciliation jobs.