Unity C# Scripting

Script Fundamentals

C# scripts (.cs files) are stored in the Assets folder. Scripts gain Unity functionality by inheriting from built-in types:

• UnityEngine.Object -- Makes custom types assignable to Inspector fields
• MonoBehaviour -- Attaches to GameObjects as components to control behavior in a scene
• ScriptableObject -- Standalone data assets not attached to GameObjects

Scripts operate in two contexts:

• Runtime scripts -- Execute in the Player build (use UnityEngine namespace)
• Editor scripts -- Run only in the Editor (use UnityEditor namespace, place in Editor folders)

MonoBehaviour Lifecycle

MonoBehaviours always exist as a Component of a GameObject. The lifecycle event functions execute in a strict order. You cannot rely on the order in which the same event function is invoked for different GameObjects unless configured via Script Execution Order settings.

Execution Order (ASCII Diagram)