Returned Copy - Swift Programming

A method can return an updated copy instead of changing the original value.

Build an updated value

returned_copy.swift

struct Settings {
    var level: Int

    func withLevel(_ nextLevel: Int) -> Settings {
        var copy = self
        copy.level = nextLevel
        return copy
    }
}

let selectedLevel = 
let base = Settings(level: 0)
let updated = base.withLevel(selectedLevel)
let message = "base=\(base.level), updated=\(updated.level)"

print(message)

struct Settings {
    var level: Int

    func withLevel(_ nextLevel: Int) -> Settings {
        var copy = self
        copy.level = nextLevel
        return copy
    }
}

let selectedLevel = 
let base = Settings(level: 0)
let updated = base.withLevel(selectedLevel)
let message = "base=\(base.level), updated=\(updated.level)"

print(message)

struct Settings {
    var level: Int

    func withLevel(_ nextLevel: Int) -> Settings {
        var copy = self
        copy.level = nextLevel
        return copy
    }
}

let selectedLevel = 
let base = Settings(level: 0)
let updated = base.withLevel(selectedLevel)
let message = "base=\(base.level), updated=\(updated.level)"

print(message)

copied update Returning a modified copy keeps the original value available for comparison.