Generics ngidini sampeyan nulis classes lan methods sing parameterized karo tipe, nyediakake type safety lan reusability tanpa duplikasi kode utawa casting. Constraints mbatasi tipe apa sing bisa dadi parameter generic, ngidini panganggone aman saka anggota-anggone. Generics nyebar luas ing C# (seluruh collections library nggunakake).
=> arr[i];
=> arr[i];
x = Get([] { , , }, );
Generics mindahake errors tipe saka runtime (casting object) menyang compile time, lan ngilangi casts — kode sing aman lan bisa digunakake maneh.
public class Box<T> // a generic class
{
private T _value;
public void Set(T value) => _value = value;
public T Get() => _value;
}
var box = new Box<string>(); // T = string, type-safe
// generic method
public T Max<T>(T a, T b) where T : IComparable<T> // constraint (see below)
=> a.CompareTo(b) > 0 ? a : b;
where T : class // T must be a reference type
where T : struct // T must be a value type
where T : new() // T must have a parameterless constructor
where T : IComparable<T> // T must implement an interface (so you can call its members)
where T : BaseClass // T must derive from BaseClass
// example: constraint lets you call CompareTo safely
public T Max<T>(T a, T b) where T : IComparable<T>
=> a.CompareTo(b) > 0 ? a : b; // CompareTo is available because of the constraint
Constraints (where T : ...) mbatesi apa sing bisa dadi T, sing ngidini sampeyan aman nggunakake anggota-anggote tipe kasebut (contone constraining menyang IComparable<T> ngidini sampeyan nelpon CompareTo). Tanpa constraint, T bisa apa wae, dadi sampeyan ora bisa nganggap anggota apa pun.
List<T>, Dictionary<K,V>, IEnumerable<T>, Task<T>, Nullable<T> ...
→ the entire collections library and much of .NET is generic.
Generics adalah fondasi C# — digunakake kanthi nyebar luas (seluruh collections library, Task<T>, IEnumerable<T>, lan API lanang-lanang generic), dadi pamahaman babagan generics perlu kanggo pengembangan C# apa pun.
Generics ngrampungi masalah nyata: nulis kode sing bisa digunakake maneh sing kerja kanggo multiple types nalika tetep type safety — alternatif (nggunakake object lan casting) ngorbanin compile-time safety lan mbutuhake casts sing rawan kesalahan, nalika nduplikasi kode saben tipe ora bisa dikendali.
Generics menehi sampeyan kode reusable, type-safe tanpa casting lan compile-time error checking. Constraints (where T : ...) minangka komplemen penting: mbatesi apa sing bisa dadi type parameter, sing bisa ngidini panganggone aman saka anggota-anggote tipe (constraining menyang interface ngidini nelpon method-metode) lan masani panganggone sing bener.
Pamahaman babagan generic classes lan methods, carane type inference kerja, lan constraints (class, struct, new(), interface/base-class constraints) perlu kanggo nggunakake .NET libraries sing puno generics kanthi efektif lan nulis abstraksi reusable, type-safe dhewe.
Amarga generics dadi dasar collections C# lan akeh saka framework, lan amarga generics minangka kunci kanggo kode type-safe reusable, ngudal generics lan constraints minangka pengetahuan core, asring-asring diterapake kanggo pengembangan C# efektif lan topik umum sing ngandhut pamahaman babagan type-safe, reusable design.