SOLVED: Help appreciated on day 41.

@Nanometer54

Oct '22

Hey its me again with yet another snippet of code that i dont understand here it is

init(mission: Mission, astronauts: [String: Astronaut]) {
    self.mission = mission

    self.crew = mission.crew.map { member in
        if let astronaut = astronauts[member.name] {
            return CrewMember(role: member.role, astronaut: astronaut)
        } else {
            fatalError("Missing \(member.name)")
        }
    }
}

what does map do here? also what does member stand for? isnt map for changing values?

@roosterboy HWS+

Oct '22

map is for taking a collection of things and transforming it into a collection of some other things.

In this case, you are taking an array of CrewRole items and transforming it into an array of CrewMember items.

member is the item being passed into the map's closure.

@Nanometer54

Oct '22

@roosterboy thanks a lot! i presume map can also be used on singular variables and not only collections right? also what exactly would member be here? an instance of the mission struct?

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