Apa bedane antara == lan === ?

Question

Accepted Answer

**`===`** (strict equality) mbandhingke nilai **lan** tipe tanpa konversi. **`==`** (loose equality) nglakoni **type coercion** dhisik, kang nyebabke asil kang nggumunake.

```js
0 == "0";    // true  — "0" coerced to 0
0 == "";     // true  — "" coerced to 0
0 == false;  // true  — false coerced to 0
null == undefined; // true  — special rule
"" == false; // true

0 === "0";   // false — different types, no coercion
NaN === NaN; // false — NaN is never equal to anything
```

## Mengapa == iku mbahayake

Peraturan coercion ora jelas lan nyebabke bug. Tuladha, `[] == ![]` iku `true` (quirk kang ono-ono banget). Sampeyan arang-arang pengen JavaScript mubeng-mubeng ngarobah tipe sadhengah-sadhengah nalika mbandhingke.

## Uran-uraning

**Tansah gunakake `===`** (lan `!==`). Mung siji pengecualian umum sing disengaja yaiku mriksa null *utawa* undefined saligira:

```js
if (value == null) { ... } // true for BOTH null and undefined — a deliberate idiom
```

Karana apa-apa, strict equality njaga mbandhingane supaya bisa diprediksi. Kanggo mbandhingke obyek sampeyan kudu deep-equality check (padha mbandhingake referensi, dadi `{a:1} === {a:1}` iku `false`).