CODEWITHSUNDEEP
swift
Angger
Angger

Reputation: 805

Inserting empty array with loop

I want to add value to an empty array by looping another array's value

var Person : [String:String]

var data : [String:String] = [
   "name" : "John",
    "age"   : "22"
]

for (index, value) in data {
    Person[index] = value
}

And I got this error "variable Person passed by reference before being initialized"

Why is that?

Upvotes: 1

Views: 539

Answers (4)

Westside
Westside

Reputation: 685

What you are declaring here is a dictionary, not an array. The same result that is being achieved by the above code (in the answer from Vvk) could be achieved by simply writing:

var Person = [ "name" : "John", "age" : "22" ]

If you want to use a loop to add items to a dictionary then you could, but I don't see the value of it in this context.

If the aim is to set values in Person equal to the values in data then you can just write:

var Person = [String:String]()

var data = [ "name" : "John", "age"   : "22" ]

Person = data

No need for a loop, unless the wider scope of your project requires it.

Upvotes: 1

Vvk
Vvk

Reputation: 4043

Try This

// Array initialization
    var Person = [String:String]()

    var data : [String:String] = [
        "name" : "John",
        "age"   : "22"
    ]

    for (index, value) in data {
        Person[index] = value
    }

Hope it helps you.

Upvotes: 3

user3182143
user3182143

Reputation: 9599

In Objective C

#import "ViewController.h"

@interface ViewController ()
{
  NSMutableArray *arr,*arrSecond;
}

@end

@implementation ViewController

- (void)viewDidLoad 
{
   [super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
   //First Array
   arr = [[NSMutableArray alloc]initWithObjects:@"iOS",@"Android",@"Windows",@"Blackberry",@"Symbion",@"Bada",nil];
   arrSecond = [[NSMutableArray alloc]init];
   for(int i=0;i<[arr count];i++)
   {
     //Second Array inside the for loop.It is getting objects from First loop of for
     [arrSecond addObject:[NSString stringWithFormat:@"%@",[arr objectAtIndex:i]]];
   }
 }

Upvotes: 1

Daniel Kl&#246;ck
Daniel Kl&#246;ck

Reputation: 21137

change:

var Person : [String:String]

to:

var Person = [String:String]()

to initialise the array before using it.

Upvotes: 2

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