# Array

**Access**

```
from
to

without

second
third
fourth
fifth
forty_two
```

**Conversions**

```ruby
to_sentence

to_formatted_s & to_default_s & to_s

to_xml
```

**Extract\_options**

```
extract_options!
```

**Grouping**

```
in_groups
in_groups_of

split
```

**prepend and append**

```
append & <<
prepend & unshift
```

**Wrap**

```
wrap
```

**Array Inquirer**

数组可以调用期望所包含元素结尾加 `?` 以询问是否包含此元素。

或使用 `any?` 传递元素名字询问。

**其它**

```
inquiry

deep_dup

to_param
to_query
```
