Explore Capsules

Regular expressions are powerful tools for matching and validating text, but they require careful construction to avoid errors and performance issues. This collection presents practical patterns for common tasks like email and IP address validation, explains how to use anchors and assertions to control matches, and highlights strategies to prevent security risks such as catastrophic backtracking. It also covers Unicode-aware techniques and testing methods to ensure reliable and efficient regex usage.

First-aid knowledge is crucial for responding effectively to emergencies such as severe bleeding, seizures, allergic reactions, opioid overdoses, and injuries involving broken bones or eye trauma. This collection provides clear guidelines on when to call emergency services, how to perform CPR, safely remove ticks, use epinephrine auto-injectors, and apply pressure to control bleeding. It also covers important safety precautions like avoiding harmful actions such as putting objects in a seizure victim’s mouth or attempting to realign broken bones.