> For the complete documentation index, see [llms.txt](https://osl.mistium.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://osl.mistium.com/methods/objects/accessing.md).

# Keys, Values & Membership

Read the contents of an object. None of these mutate.

#### `.getKeys()` → `string[]`

The object's keys. Object keys are always strings, so this remains `string[]` even when the object values are dynamic.

#### `.getValues()` → `any[]`

The object's values. When the compiler knows the object field types, it preserves those types in the returned array; homogeneous inferred objects therefore return `T[]`.

#### `.getEntries()` → `array`

The object as an array of `[key, value]` pairs.

Keys, values, and entries all use the same sorted visible-key order. The three enumeration methods take no arguments and report `requires no parameters` otherwise; `.contains` takes exactly one key.

#### `.contains(key)` → `boolean`

Whether the object has the given key.

```javascript
object o = { a: 1, b: 2 }
log o.getKeys()      // ["a", "b"]
log o.getValues()    // [1, 2]
log o.getEntries()   // [["a", 1], ["b", 2]]
log o.contains("a")  // true
```

> Read a single value through the same lookup with index syntax (`o["a"]` or `o.a`) or `.item(key)`. The inverse of `.getEntries()` is the array method [`.toEntriesObj()`](/methods/arrays/converting.md).