# C# Generics, Statics **C# Generics** provide a way to write code that can be used with a variety of different data-types, you'll recognize code that uses Generics when you see this type of code**`< T >`**. The **T** represents a place-holder for a data-**type** that is specified when you write the code, depending on the type of data used in your code. **UnityEngine:** Example: **GetComponent< T >** \ All script components we write inherit from MonoBehaviour, and MonoBehaviour inherits from the Component Class. This allows us to use methods from the Component class without specifying an object to execute the method.\ See [Generics: Unity Manual ](https://docs.unity3d.com/Manual/GenericFunctions.html) \ **Unity Example:** \ GetComponent Method returns an object of the specified placeholder datatypes\ `T tvariableName = GetComponent< T >( );` \ `Animator animator = GetComponent< Animator >( );` \ `MyComponent mc = GetComponent< MyComponent >( ); //custom component` **C# Data-structures** are classes defined in the C# language. C# provides many Data-Structures that use Generics: We'll work with the following Data-structures that implement C# Generics in this course, in all cases, our code will specify the datatype that replaces the **type** placeholder **T**\ \ **C# Examples:**\ \&#xNAN;**`List< T >, Dictionary< Tkey, Tvalue > , Queue< T >`**\ \ **`List< GameObject > list = new List< GameObject >( ); //list of GameObjects`** **UnityEngine Foundational Classes: Script API**\ When we write code, we'll primarily work with code from the UnityEngine Library, where 3 of the main base classes we'll use are listed below with links to the Scripting API\ [**Object:**](https://docs.unity3d.com/ScriptReference/Object.html) Base class for all objects Unity can reference.\ [**GameObject:**](https://docs.unity3d.com/ScriptReference/GameObject.html) Base class for all entities in Unity Scenes.\ [**Component**](https://docs.unity3d.com/ScriptReference/Component.html)**:** Base class for everything attached to [GameObjects.](https://docs.unity3d.com/ScriptReference/GameObject.html)
### C# Static Methods, Variables \ When a **method or variable** is specified as **static,** it means that there's no need to create an object instance of that class in order to use the method. Instead, a method can be executed using the ClassName and dot notation to execute a method. If a **class** is specified as static, then all **variables and methods** within the class must be specified as static. When variables, methods, or classes are specified as static, the access modifier is usually specified as public.\ The example below shows that the **Mathf** library has a static method: **Abs( float x )**\ We can see that to call the Abs( ) method, we can use the name of the class itself.\ \ Example: **`bool isWalking = Mathf.Abs( inputX ); //static method`**\ \ Normally, to call a method, you must have initialized a object, then the object executes the method. Example: \ \ `Zombie myZombie = new Zombie( );` //initialize an object using constructor\ `myZombie.dance( "samba");` //object uses dot notation to execute method\ \ We can see this used in Unity with the GameObject class **static methods** shown below.\ **A static variable** **is associated with the class itself.** It is not associated with an object instance of the class. This means that **there is only one of instance of a static variable in existence when a program** is executing, the variable is associated with the class rather than an object instance. **Static variables** will be used when creating a **Singleton** gameObjects.\ \ **Unity Example: Static Method: `GameObject.Find( );`**\ \ [**Static GameObject Methods:** ](https://docs.unity3d.com/ScriptReference/GameObject.html)\ `GameObject.Find( "someGameObjectName" )`\ `GameObject.FindWithTag( "SomeTag" )`\ `GameObject.FindGameObjectsWithTags( "SomeTag" )`