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swiftnsnumber

Absorb value from NSNumber

let Rating = self.currentPerson.Rating // This is a NSNumber

Rating -= 1

What I'm trying to do, is to take an x value from the Rating, and then print the new value of Rating.

How do I do this properly?

Solution

  • To perform this operation in the way you wish you need to write your own function for handling it:

    infix operator -=

func -=(lhs:inout NSNumber, rhs:Double) {
    lhs = NSNumber(value: lhs.doubleValue - rhs)
}

    You also need to use a variable rather than a constant in your implementation:

    var Rating = self.currentPerson.Rating // This is a NSNumber

Rating -= 1

    So that the value can be changed.