查询对象不存在

Question

我有此数组：

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

我申请以下它：

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

如果没有搜索对象，也没有地址对象，代码产生了一个错误：

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中处理类似的东西的方式是什么？

Answer 1

首先...

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

只是为了澄清，它实际上是一个专门Hash。

其次...

你可以做这样的事情：

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