Terms starting with "F"
Forward Secrecy
PHP 7.4+
A key-exchange property where ephemeral session keys are discarded after use, so a future compromise of long-term keys cannot decrypt past sessions.
CWE-327 OWASP A02:2021-Cryptographic Failures
3d ago
cryptography advanced
5.9
Fenwick Tree (Binary Indexed Tree)
PHP 7.4+
1
A compact array-backed structure giving O(log n) prefix-sum queries and O(log n) point updates with minimal code and memory overhead.
2w ago
data_structures advanced
Fetch API
ES2015
The browser-native Promise-based API for making HTTP requests — replacing XMLHttpRequest with a cleaner interface supporting streaming, CORS, and request/response objects.
2mo ago
javascript beginner
FFI — Foreign Function Interface (PHP 7.4)
PHP 7.4+
PHP 7.4 FFI allows calling C functions and accessing C data structures directly from PHP — enabling Python-like ctypes integration for native libraries without writing C extensions.
2mo ago
php advanced
Fibers — Cooperative Concurrency (PHP 8.1)
PHP 8.1+
PHP 8.1 Fibers enable cooperative multitasking — suspending execution at yield points and resuming later — the foundation for async PHP frameworks without OS threads.
2mo ago
php advanced
File Permissions
PHP 4.0+
Unix permission bits (owner/group/world read-write-execute) that control which processes can read, write, or execute files — misconfigured permissions are a common PHP deployment and security issue.
2mo ago
php beginner
Four Golden Signals
Google SRE's Four Golden Signals — Latency, Traffic, Errors, Saturation — are the four metrics that, if monitored and alerted on, cover most production reliability concerns.
2mo ago
observability beginner
Fatal Errors vs Errors vs Warnings
PHP 5.0+
PHP has three error levels that behave very differently: fatal errors halt execution, warnings continue but signal problems, and notices are advisory only.
2mo ago
php beginner
File API — FileReader & File Input
ES2015
File and FileReader provide client-side access to user-selected files before upload to PHP — enabling preview, validation, and chunked upload.
3mo ago
javascript intermediate
FormData API
ES2015
FormData constructs key-value pairs from HTML forms for AJAX submission to PHP backends — supports file uploads without page reload.
3mo ago
javascript intermediate
Feature Teams vs Component Teams
Feature teams own end-to-end delivery across the stack; component teams own a layer — feature teams ship faster but need platform support.
3mo ago
general intermediate
Fiber-Based Task Scheduler
PHP 8.1+
Building a cooperative multitasking scheduler with PHP Fibers — suspending and resuming tasks at I/O wait points to run multiple tasks concurrently in a single thread.
3mo ago
php advanced
File Descriptors & ulimit
PHP 5.0+
File descriptors are integer handles for open files, sockets, and pipes — each process has a limit (ulimit -n), and exhausting them causes 'too many open files' errors.
3mo ago
linux intermediate
Fluent Builder Pattern
Returns $this from each setter enabling method chaining — used in query builders, test factories, and configuration objects.
3mo ago
quality intermediate
Function & Method Naming Convention
PHP functions and methods use camelCase per PSR-1 — lowercase first word, each subsequent word capitalised, verb-noun pairs for actions.
3mo ago
style beginner
Fuzz Testing
PHP 7.0+
Automatically generating random, unexpected, or malformed inputs to find crashes, assertion failures, and security vulnerabilities that manual test cases miss.
3mo ago
testing advanced
Facade Pattern
PHP 5.0+
Provides a simplified, unified interface to a complex subsystem, hiding its internal complexity from clients.
3mo ago
quality beginner
Faceted Search & Aggregations
Dynamically computed counts for filter categories based on current results — the 'Brand (42) | Price $0-50 (18)' sidebar that refines search results.
3mo ago
search intermediate
Factory Pattern
Delegates object creation to a dedicated factory, decoupling the creator from the created class and allowing subclass instantiation.
3mo ago
general intermediate
Fail Fast Principle
Detect and report errors at the earliest possible point rather than allowing invalid state to propagate and cause confusing failures elsewhere.
3mo ago
quality beginner