How to print variables in structs in arrays?

Question

With this Swift 3.0 lines:

struct Person {
    var name: String
    var surname: String
    var phone: Int
    var isCustomer: Bool
}
var contacts: [Person] = []
contacts.append(Person(name: "Jack", surname: "Johnson", phone: 2, isCustomer: false))
contacts.append(Person(name: "Mike", surname: "Morris", phone: 3, isCustomer: true))

I have created an array that includes two structures which include 4 variables each. I can print a single object of the array like this: print(contacts[0].name) but is there any way to print all the Strings of the name section at once?

Frankie · Accepted Answer · 2016-11-12 18:47:55Z

6

Learn how to use map. I use it all the time.

print(contacts.map({ $0.name }))

Search for map in this Apple Documentation about Closures

answered Nov 12, 2016 at 18:47

Frankie

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1 Comment

mfaani Over a year ago

I think using forEach as par is using in the other answer is better. since you don't want to create a new variable, rather you just want to do something. Also for learning about closures and higher order functions I find this tutorial to be of the best.

par · Accepted Answer · 2016-11-12 18:59:12Z

2

You'll have to iterate over the array, either printing the values as you go, or capturing them into a string and printing them all at once.

Here's one way:

for contact in contacts {
    print(contact.name)
}

Here's another:

contacts.forEach { print($0.name) }

Finally, you could join all the strings into one value with a separator and just print once. When you do it this way the joinWithSeparator function iterates the array for you:

let names = contacts.map { $0.name }
let joinedNames = names.joinWithSeparator(" ")

print(joinedNames)

edited Nov 12, 2016 at 18:59

answered Nov 12, 2016 at 18:50

par

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Comments

lmiguelvargasf · Accepted Answer · 2016-11-13 05:32:24Z

2

You should implement the protocol CustomStringConvertible by defining the computed property description:

struct Person: CustomStringConvertible {
    var name: String
    var surname: String
    var phone: Int
    var isCustomer: Bool

    var description: String { 
        return
            "Name: \(name)\n" + 
            "Surname: \(surname)\n" +
            "Phone: \(phone)\n" +
            "Is Customer? \(isCustomer)\n"
    }
}

And then:

var contacts: [Person] = []
contacts.append(Person(name: "Jack", surname: "Johnson", phone: 2, isCustomer: false))
contacts.append(Person(name: "Mike", surname: "Morris", phone: 3, isCustomer: true))
print(contacts)

Obviously you can define description as you want.

edited Nov 13, 2016 at 5:32

answered Nov 13, 2016 at 5:25

lmiguelvargasf

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