Filtering a multi-dimensional array in swift

Question

I am trying to filter a multi-dimensional array. Below is my swiftUI view.

import SwiftUI

struct Person {
    let name: String
    let job: String
    let age: Int
    let rating: Rating
    enum Rating: String {
        case Poor, Ok, Good, Excellent
    }
}


extension Person: CustomStringConvertible {
    var description: String {
        "Name: \(name), Job: \(job), Age: \(age), Rating: \(rating)"
    }
}

struct view: View {
    
    let name = "Paul"
    var array2d: [[String]].map(Person.init)
    let person = array2d.first(where: {$0.name == name})
    
    var body: some View {
        
        ZStack{
        Color.white
            Text("\(self.person)")
            
        }
            
        
    }
    
}

array2d is passed from the ViewController to the swiftUI view and it looks like this:

var array2d = [[Paul, CEO, 30, Good], [John, Manager, 45, Ok], [Scott, Assistant, 22, Poor], [Robert, CEO, 67, Excellent], [Paul, CEO, 56, Poor], [John, Manager, 23, Good]]

I am getting several errors with the the above code:

on var array2d: [[String]].map(Person.init) the errors:

Consecutive declarations on a line must be separated by ';'
Expected declaration

and on let person = array2d.first(where: {$0.name == name})

Cannot use instance member 'array2d' within property initializer; property initializers run before 'self' is available

Cannot use instance member 'name' within property initializer; property initializers run before 'self' is available

Value of type '[String]' has no member 'name'

I'd recommend to have a struct instead of an array to represent a person. Like struct Person { let name: String; let role: StringOrEnum, let age: Int, let someEnum: SomeEnumWithGoodOkExcellentEtc}. And you want to filter or find the first(where:). Imagine we have 2 "Paul"s: let paul = array2d.first(where: { $0.first == person } or let filtered = array2d.filter{ $0.first == person }? — Larme
– Larme, Commented Sep 25, 2020 at 16:23
@Jdv It is Swift naming convention to name all your classes, structures, enumerations and protocols starting with an Uppercase letter. struct AView: View {. For your cases, methods and variables they should start with a lowercase letter. case poor = "Poor", ok = "Ok", good = "Good", excellent = "Excellent" — Leo Dabus
– Leo Dabus, Commented Sep 25, 2020 at 21:27
Not related to your question but I think you should first try to learn the basics of the language (Swift) and UIKit framework. SwiftUI is too complex for beginners. — Leo Dabus
– Leo Dabus, Commented Sep 25, 2020 at 21:33
Is your data coming from a simple text file? Have you considered using a JSON String? — Leo Dabus
– Leo Dabus, Commented Sep 25, 2020 at 21:37
Appreciate your feedback on the previous comment @LeoDabus . My dafa is coming from a text file. — Jdv
– Jdv, Commented Sep 25, 2020 at 22:38

Leo Dabus · Accepted Answer · 2020-09-25 17:21:37Z

1

A direct answer to your question you can get the first array where the first element is equal to person:

let person = "Paul"
let array2d = [["Paul", "CEO", "30", "Good"], ["John", "Manager", "45", "Ok"], ["Scott", "Assistant", "22", "Poor"], ["Robert", "CEO", "67", "Excellent"], ["Paul", "CEO", "56", "Poor"], ["John", "Manager", "23", "Good"]]
if let array = array2d.first(where: {$0.first == person}) {
    print(array)  // ["Paul", "CEO", "30", "Good"]
}

But what you really should do is to struct your data and search your array by its name property:

struct Person {
    let name: String
    let job: String
    let age: Int
    let rating: Rating
    enum Rating: String {
        case poor, regular, good, excellent
    }
}

extension Person: CustomStringConvertible {
    var description: String {
        "Name: \(name), Job: \(job), Age: \(age), Rating: \(rating)"
    }
}

let name = "Paul"
let people = [("Paul", "CEO", 30, .good), ("John", "Manager", 45, .regular), ("Scott", "Assistant", 22, .poor), ("Robert", "CEO", 67, .excellent), ("Paul", "CEO", 56, .poor), ("John", "Manager", 23, .good)].map(Person.init)
if let person = people.first(where: {$0.name == name}) {
    print(person)  // "Name: Paul, Job: CEO, Age: 30, Rating: good\n"
}

answered Sep 25, 2020 at 17:21

Leo Dabus

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3 Comments

Jdv Over a year ago

Thank you. That works in the dummy example I used, however I can't get it to work in the real swiftUI view I am using. I edited my question to show the swiftUI view I am working with. One thing I noticed is that the property people you created separates each array with (), in my case they are separated by [].

Leo Dabus Over a year ago

It is just a way I used to create an array of Person. It wasn’t my intention to shout how to parse your data

Jdv Over a year ago

I understand. I edited my question to show how I tried to implement your solution and the errors I am getting. I am pretty new to swift and likely missing something obvious here. Thanks

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