查詢對象不存在

Question

我有此數組：

--- !map:ActiveSupport::HashWithIndifferentAccess 
search: !map:ActiveSupport::HashWithIndifferentAccess 
    address: test 

我申請以下它：

address = params['search']['address'] 
if address 
    # do something 
end 

如果沒有搜索對象，也沒有地址對象，代碼產生了一個錯誤：

You have a nil object when you didn't expect it! You might have expected an instance of Array. The error occurred while evaluating nil.[]

在ruby中處理類似的東西的方式是什麼？

Answer 1

首先...

[...] for example i have this array:

只是爲了澄清，它實際上是一個專門Hash。

其次...

你可以做這樣的事情：

if params[:search] and params[:search][:address] 
    # do something with address 
else 
    # no value given 
end