Terms starting with "I"
Iterating Objects with foreach (Iterator & IteratorAggregate)
PHP 5.5+
3
foreach can traverse any object implementing Iterator or IteratorAggregate, not just arrays — control iteration without exposing internal state.
1w ago
PHP intermediate
iptables and netfilter
Kernel packet-filtering framework (netfilter) and its classic userspace tool (iptables) for firewalling, NAT, and packet mangling.
2w ago
Linux advanced
Inline Expansion
5
A compiler optimization that replaces a function call with the body of the called function, eliminating call overhead and unlocking further optimizations.
3w ago
Compiler advanced
Internal Developer Platform (IDP)
A curated, self-service layer on top of cloud and CI/CD infrastructure that product teams use to ship services without filing tickets — paved roads that make the right thing the easy thing.
2mo ago
DevOps intermediate
Insecure Deserialization
Deserializing attacker-controlled data can trigger arbitrary object construction and method calls — PHP's unserialize() with untrusted input enables remote code execution via gadget chains in the loaded class graph.
CWE-502 OWASP A8:2021
3mo ago
Security advanced
Image Optimisation
Reducing image file size and delivery overhead through format choice (AVIF, WebP), compression, responsive sizing (srcset), lazy loading, and explicit dimensions — the single highest-impact performance lever for most websites.
3mo ago
Performance intermediate
InnoDB vs MyISAM
InnoDB is the default MySQL storage engine supporting transactions, foreign keys, and row-level locking — MyISAM is legacy with table-level locking and no transaction support.
3mo ago
Database beginner
INSERT ... ON DUPLICATE KEY UPDATE
PHP 5.1+
An atomic MySQL upsert — inserts a new row or updates the existing one if a unique key constraint would be violated.
3mo ago
Database intermediate
ICU Message Format
PHP 7.0+
1
A standard syntax for translatable strings that handles pluralisation, gender, number formatting, and date formatting in a single expression — supported by PHP's intl extension via MessageFormatter.
3mo ago
i18n intermediate
Import Maps
ES2020
2
Import maps let browsers resolve bare module specifiers (import 'lodash') without a bundler — mapping module names to URLs in a JSON script tag.
3mo ago
JavaScript intermediate
infer Keyword in Conditional Types
2.8
The infer keyword inside conditional types lets TypeScript extract and name a type from within a generic structure — enabling ReturnType<T>, Awaited<T>, and custom type extraction.
3mo ago
TypeScript advanced
Inline Temp Variable Refactoring
Inline Temp removes a temporary variable used only once when its name adds no clarity — replacing the variable reference with its expression directly.
3mo ago
Code Quality beginner
Intersection & DNF Types in Practice
PHP 8.1+
PHP 8.1 intersection types (A&B) and PHP 8.2 DNF types ((A&B)|null) allow precise type constraints for objects implementing multiple interfaces.
3mo ago
PHP advanced
IntersectionObserver API
HTML5
IntersectionObserver fires when an element enters or leaves the viewport — the modern way to implement lazy loading, infinite scroll, and scroll-triggered animations.
3mo ago
JavaScript intermediate
Inverted Index
A data structure that maps each unique word to the list of documents containing it — the foundation of all full-text search engines, enabling fast lookup of documents matching a query term.
3mo ago
Search intermediate
IoC Container
PHP 7.0+
An Inversion of Control container automatically resolves and injects class dependencies — you declare what a class needs, the container figures out how to create it, eliminating manual dependency wiring.
3mo ago
Code Quality intermediate
Implicit Globals & strict mode
ES5
Assigning to an undeclared variable in non-strict mode silently creates a global — use 'use strict' or ES modules to prevent accidental global pollution.
3mo ago
JavaScript intermediate
Integer Overflow & PHP_INT_MAX
PHP 4.0+
PHP integers silently overflow to float when exceeding PHP_INT_MAX (9.2×10¹⁸ on 64-bit) — use BCMath or GMP for arbitrary precision arithmetic.
3mo ago
PHP intermediate
IndexedDB
ES2015
Browser-native NoSQL database for offline-capable PHP web apps — stores structured data that survives page reloads, complements service workers.
3mo ago
JavaScript advanced
Image Optimisation
PHP 7.0+
Serving images in modern formats (WebP, AVIF), at the correct size, with appropriate compression — typically the single biggest performance win for image-heavy pages.
3mo ago
Performance intermediate