how to store a value like "2.3.1" in Numbers in iOS?

Question

I want to store a value something like 3.2.7 in Numbers in iOS, coz I want to compare the value with other.

Is there any data type is available? or any tricks?

anyone have a solution for this?

Answer 1

If you wanted to implement something like that in Swift you could probably get away with something like the following:

struct Version: Comparable, Equatable {

    static func == (lhs: Version, rhs: Version) -> Bool {
         return lhs.maj == rhs.maj && lhs.min == rhs.min && lhs.patch == rhs.patch
    }

    static func < (lhs: Version, rhs: Version) -> Bool {
        if lhs.maj < rhs.maj || lhs.min < rhs.min || lhs.patch < rhs.patch { return true }
        return false
    }

    var maj: Int
    var min: Int
    var patch: Int

    var formatted: String {
        return "\(maj).\(min).\(patch)"
    }
}

let v1 = Version(maj: 1, min: 2, patch: 2)
let v2 = Version(maj: 1, min: 2, patch: 2)
let v3 = Version(maj: 2, min: 2, patch: 2)
let v4 = Version(maj: 1, min: 3, patch: 2)
let v5 = Version(maj: 1, min: 2, patch: 3)

print (v1 == v2)
print (v1 == v3)
print (v1 > v2)
print (v1 > v3)
print (v1 > v4)
print (v1 > v5)
print (v3 > v4)
print (v3 > v5)

print (v1.formatted)
print (v2.formatted)
print (v3.formatted)
print (v4.formatted)
print (v5.formatted)

Answer 2

This is almost certainly a duplicate of Compare version numbers in Objective-C.

As the accepted answer there tells you, strings like @"3.2.1" and @"2.3.7" are strings, not numbers — but they can be compared in the intuitively numeric way as version strings, by calling compare:options: with the NSNumericSearch option.

And if that doesn't quite satisfy your needs, other answers provide many useful tweaks to the comparison algorithm.