Apa tegese keyword static lan final?

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**`static`** berarti "kasedhiakan kelas dhewe, dudu instance." **`final`** berarti "ora bisa diganti/dilanjutake." Isih keyword sing kapisah kang asring dikacaukan, nanging ngatasi kapentingan berlainan — lan nalika digabung ndadhimake konstanta. ## static — level kelas, dibagi kabeh instance ```java public class Counter { static int count = 0; // ONE shared variable for the whole class int id; // each instance has its OWN id Counter() { count++; // increments the shared counter id = count; } static void reset() { // static method — called on the class count = 0; } } Counter.count; // access via the CLASS name, no instance needed Counter.reset(); // call a static method on the class new Counter(); // each new instance shares `count` ``` Anggota `static` kasedhiakan kelas, ora obyek satunggal — ana siji salinan kang dibagi kabeh instance, diakses liwat jeneng kelas. Method static ora bisa nggunakake `this` utawa field instance (ora ana instance sing ana). ## final — ora bisa diganti / diowahi / dilanjutake ```java final int MAX = 100; // a constant — can't be reassigned MAX = 200; // ❌ compile error final class Util { } // a final CLASS can't be subclassed (e.g. String is final) class Base { final void critical() { } // a final METHOD can't be overridden } ``` `final` nduweni telung gunane: **variable** final ora bisa diganti (konstanta), **method** final ora bisa diowahi, lan **kelas** final ora bisa dilanjutake. ## Poin sing rada rumit: referensi final ```java final List list = new ArrayList<>(); list.add("a"); // ✅ ALLOWED — modifying the OBJECT, not the reference list = new ArrayList<>(); // ❌ ERROR — can't REASSIGN the reference ``` Untuke referensi `final`, *referensi* ora bisa diganti, nanging *obyek sing dinggo nunjuk* isih bisa diganti — titik kang asring nduweluk-waluh. ## Digabung: static final = konstanta ```java public static final double PI = 3.14159; // class-level, unchangeable constant public static final String APP_NAME = "MyApp"; // convention: UPPER_SNAKE_CASE for static final constants ``` `static final` babar blas gawe konstanta sejati — siji nilai sing dibagi, ora bisa diganti kanggo kabeh kelas, cara standar kanggo nemtokake konstanta ing Java. ## Mengapa iku penting `static` lan `final` keyword Java dhasar kang nduweni teges berlainan lan penting: `static` ndadhimake state level kelas lan method utilitas (counter sing dibagi, factory method, `Math.PI`, method `main` dhewe), dene `final` nglarang immutability lan nyegah inheritance/owahan (konstanta, kelas immutable kaya String, ngunci method penting). Omongke — kalebu tingkah laku final-referensi sing rumit (referensi tetep, obyek bisa diganti) lan gabungan dadi konstanta — dadi penting kanggo merancang kelas kanthi benar, nemtokake konstanta kanthi bener, ngontrol extensibility, lan mangsir babagan state sing dibagi balak state per-instance. Kabeh ana ing kode Java lan topik wawancara sing asring ditakokake.