Swift：测试非可选值是否为零/未设置

Question

I have the following line of code:

var info = [String : Any]()

Later i need to compare if info is not nil / set:

Something like this:

        if(info != nil){
            InfoCenter.default().info = info
        }

But XCode warns: Comparing non-optional value of type '[String : Any]' to nil always returns true

How can I fix this?

Thanks for any help.

Answer 1

You can check if the Dictionary is empty.

if !info.isEmpty {
    InfoCenter.default().info = info
}

Answer 2

If you're expecting info to be nil , you must declare it as an optional Dictionary like,

var info: [String:Any]?

Now, use if-let to get the value of info and check the elements in it using isEmpty , ie

if let info = info, !info.isEmpty {
    InfoCenter.default().info = info
}

Answer 3

By using following

var info = [String : Any]()

Means you have initialized info object, Which means its not nil it have a empty value. So swift compiler trying to tell you that info object will never be nil according to above declaration. To remove this warning you can do use optional binding.

var info :[String : Any]?
**OR**
var info :[String : Any]!

Answer 4

Try this

if info.count != 0
{
    InfoCenter.default().info = info            
}