Ruby Array資料結構容許，一個 Array 同時裝載多項型態的元素(element)，element 可以是 Integer, String, Hash……等等。這項特性可以用在 精簡地傳入多項參數 ，也可用在傳出多項回傳值，舉例如下：
套用前面文章「以精簡方式傳入多項參數」的例子，修改例子，變成
def method_1( dataStructure_1, dataStructure_2, array_flag_operation )
flag_operation_1 = array_flag_operation[0] # flag_operation_1 can be an object type of string or integer, float.
flag_operation_2 = array_flag_operation[1] # flag_operation_2 can be an object type of string or integer, float.
flag_operation_3 = array_flag_operation[2] # flag_operation_3 can be an object type of string or integer, float.
flag_operation_4 = array_flag_operation[3] # flag_operation_4 can be an object type of string or integer, float.
.
.
. # (produce new Objects: modify_dataStructure_1 and modify_dataStructure_2)
.
# want to return modify_dataStructure_1 and modify_dataStructure_2
return modify_dataStructure_1, modify_dataStructure_2
end
上面這個例子，無法如作者所想，回傳多個回傳值，而且會有編譯錯誤，因為 Ruby function的 return 只能回傳一個變數。
修改上面的例子如下：
def method_1( dataStructure_1, dataStructure_2, array_flag_operation )
flag_operation_1 = array_flag_operation[0] # flag_operation_1 can be an object type of string or integer, float.
flag_operation_2 = array_flag_operation[1] # flag_operation_2 can be an object type of string or integer, float.
flag_operation_3 = array_flag_operation[2] # flag_operation_3 can be an object type of string or integer, float.
flag_operation_4 = array_flag_operation[3] # flag_operation_4 can be an object type of string or integer, float.
.
.
. # (produce new Objects: modify_dataStructure_1 and modify_dataStructure_2)
.
# want to return modify_dataStructure_1 and modify_dataStructure_2
array_many_return_Value = Array.new
array_many_return_Value[0] = modify_dataStructure_1
array_many_return_Value[1] = modify_dataStructure_2
return array_many_return_Value
end
caller 或 main procedure 呼叫 callee method_1 的寫法應寫成如下：
array_returnValue_collection = method_1(dataStructure_1, dataStructure_2, array_many_flags_collection)
new_modify_dataStructure_1 = array_returnValue_collection[0]
new_modify_dataStructure_2 = array_returnValue_collection[1]
這樣即可完成回傳多項回傳值