连接操作是一个顺序的连接多个数据片段的过程，通常是连接字符串和非字符串数据(绝大多数是变量或其它字符)。
Concatenation is the process to sequentially join multiple pieces of data, usually literal strings with non-string-literal data (most commonly, variables or other literals).
无法在非顺序集合中执行该操作。
This operation cannot be performed on a non-sequenced collection.
应用推荐