How to init array of objects in objective-c, similar to swift

Question

I am new iOS developer. I started to learn Swift but I want to switch to Objective-C. Below is the code which i'm using in Swift

I have Player.swift:

import Foundation
import UIKit

struct Player {
    var name: String!
    var game: String!
    var rating: Int

    init(name:String?, game:String?, rating:Int) {
        self.name = name
        self.game = game
        self.rating = rating
    }
}

And I have one class store data Player objects data and this data is using everywhere in project:

import Foundation
let playerData = [
    Player(name: "Bill Evan", game: "call of duty", rating: 4),
    Player(name: "Linh Nguyen", game: "Alien vs predator", rating: 3)
]

My question is how to do it in Objective-C:

I'm trying to do this in Player.h:

#import <Foundation/Foundation.h>

@interface Player : NSObject

@property(nonatomic, strong) NSString *name;
@property(nonatomic, strong) NSString *game;
@property int rating;

-(id)initWithPlayer:(NSString *)name
               game:(NSString*)game
             rating:(int)rat;

@end

And in Player.m:

#import "Player.h"

@implementation Player

-(id)initWithPlayer:(NSString *)name game:(NSString *)game rating:(int)rating {
    self.name = name;
    self.game = game;
    self.rating = rating;
    return self;
}
@end

How to create array of Player object store many players object?

You should use instancetype in init methods instead of id — Cy-4AH
– Cy-4AH, Commented Oct 6, 2016 at 9:52

MarkHim · Accepted Answer · 2016-10-06 12:50:24Z

4

Not recommended:

If you just do

NSArray *players = @[ ... see above ... ];

You would have to cast like this

Player *steven = (Player *)players[0];

Also this is more dangerous, since the compiler would also allow you to do this:

NSArray *players = @[
    [[Player alloc] initWithPlayer:@"Steven" game:@"Pokémon Go" rating:100],
    @"Just a String, not a Player object"
];

This could obviously result in a runtime crash when you're casting the @"Just a String, ..." object (players[1]) to a Player object.

edited Oct 6, 2016 at 12:50

answered Oct 6, 2016 at 9:58

MarkHim

5,7665 gold badges34 silver badges65 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

nhlinh Over a year ago

oh, thank you so much @MarkHim. i'm just beginer in ios development :)

nhlinh Over a year ago

One thing, if i create class that store this Array and using it in everywhere in my app. How about this class ?. thank you !

MarkHim Over a year ago

I'm not sure if i understand correctly, but with #import you can import class headers to other objective c files. Simply Do #import "Players.h" in any other objective-c .h or .m file

GeneCode Over a year ago

This answer is neat.

nhlinh Over a year ago

@MarkHim so sorry, my wrong question. :) thank you !

Clarence Leung · Accepted Answer · 2016-10-06 09:50:48Z

To answer the question, you can initialize arrays of objects in Objective-C / Foundation with either one of two methods:

// Original, longer way of doing it
NSArray *words = [NSArray arrayWithObjects:@"list", @"of", @"words"];

// Modern Objective-C shorthand
NSArray *words = @[@"list", @"of", @"words"];

A little bit more verbose, but given your object, here's how your Swift code:

let playerData = [
    Player(name: "Bill Evan", game: "Call of Duty", rating: 4),
    Player(name: "Linh Nguyen", game: "Alien vs. Predator", rating: 3)
]

Would look in Objective-C:

NSArray *playerData = @[
    [[Player alloc] initWithPlayer:@"Bill Evan" game:@"Call of Duty" rating:4],
    [[Player alloc] initWithPlayer:@"Linh Nguyen" game:@"Alien vs. Predator" rating:3]
];

Collectives™ on Stack Overflow

How to init array of objects in objective-c, similar to swift

2 Answers 2

Recommended:

Not recommended:

5 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Recommended:

Not recommended:

5 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related