I have a NSManagedObject subclass with an optional instance variable
@NSManaged var condition: NSNumber? // This refers to a optional boolean value in the data model
I'd like to do something when the condition variable exists and contains 'true'.
Of course, I can do it like this:
if let cond = condition {
if cond.boolValue {
// do something
}
}
However, I hoped it would be possible to do the same thing a little bit more compact with optional chaining. Something like this:
if condition?.boolValue {
// do something
}
But this produces a compiler error:
Optional type '$T4??' cannot be used as a boolean; test for '!= nil' instead
The most compact way to solve this problem was this:
if condition != nil && condition!.boolValue {
// do something
}
Is there really no way to access the boolean value with optional chaining, or am I missing something here?
You can just compare it to a boolean value:
if condition == true {
...
}
Some test cases:
var testZero: NSNumber? = 0
var testOne: NSNumber? = 1
var testTrue: NSNumber? = true
var testNil: NSNumber? = nil
var testInteger: NSNumber? = 10
if testZero == true {
// not true
}
if testOne == true {
// it's true
}
if testTrue == true {
// It's true
}
if testNil == true {
// not true
}
if testInteger == true {
// not true
}
The most interesting thing is that 1 is recognized as true - which is expected, because the type is NSNumber
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