How to add nil value to Swift Dictionary?

Question

I have made a request to my server in my app. And posted data something like this.Server side is waiting for all parameters even they are nil. But i couldn\'t add nil values to

Answer 1

To add a nil value to a dictionary in Swift, your dictionary's values must be of the Optional type.

Consider a Person class:

class Person {
    let name: String
    weak var spouse: Person?

    init(name: String, spouse: Person?) {
        self.name = name
        self.spouse = spouse
    }
}

Instances of the Person type can have a name and an optional spouse. Create two instances, and add the first to a dictionary:

let p1 = Person(name: "John", spouse: nil)
let p2 = Person(name: "Doe", spouse: p1)
p1.spouse = p2
var people = [p1.name: p1.spouse]

This dictionary (called people) maps names to spouses, and is of type [String: Person?]. You now have a dictionary with a value of Optional type: Person?.

To update the value of the key p1.name to be nil, use the updateValue(_: forKey:) method on the Dictionary type.

people.updateValue(nil, forKey: p1.name)
people[p1.name] 

The value for the key p1.name is now nil. Using updateValue(_: forKey:) is a bit more straightforward in this case because it doesn't involve making a throwaway instance, setting it to nil, and assigning that instance to a key in a dictionary.

NB: See rintaro's answer for inserting null into a post's dictionary.