(string) compound                          (delimiter = '_')
          
    複数の単語を連結して複合語を生成します。
Parameters:
| name | type | default | caption | 
|---|---|---|---|
| delimiter | string | '_' | Delimiter. | 
Returns:
- (string) — Compound words.
Author:
- StewEucen
Since:
- Version 1.0.0
Examples:
['camel', 'Case'].compound()          #=> "camelCase"
['Studly', 'Caps'].compound()         #=> "StudlyCaps"
['XML', 'HTML', 'Request'].compound() #=> "XML_HTMLRequest"
['get', 'utc_', 'day'].compound()     #=> "get_utc__day"
['', 'webkit', 'flex'].compound('-')  #=> "-webkit-flex"