CODEWITHSUNDEEP
iosswift
X Pahadi
X Pahadi

Reputation: 7443

iOS Swift Error: Execution was interrupted, reason : signal SIGABRT

I am trying to execute the following code in a playground. Fairly, I am treating both variables bm and ul equally but error shows only at ul

import UIKit

let defaults = NSUserDefaults.standardUserDefaults()
defaults.setObject([], forKey: "bookmarks")
defaults.setObject([], forKey: "urls")

var bm : NSMutableArray = defaults.valueForKey("bookmarks") as NSMutableArray
var ul : NSMutableArray = defaults.valueForKey("urls") as NSMutableArray

bm.addObject("Google")                 //--->Works
ul.addObject("http://google.com")      //--->Oops, No

Upvotes: 1

Views: 6881

Answers (1)

Paulw11
Paulw11

Reputation: 114975

I can't tell you why the first works and the second doesn't - it is probably just a quirk of playgrounds, timing and a delay in persisting NSUserDefaults to disk.

Your problem, however, is that valueForKey (and you should use objectForKey) returns immutable objects - so bm and ul will actually be NSArray instances and you can't simply cast them to NSMutableArray. You get a crash when you try to do so and mutate the object.

You need to create a mutable copy of your array. 

 var bm=defaults.objectForKey("bookmarks") as NSArray?

 if bm != nil {
    var bmCopy=bm!.mutableCopy() as NSMutableArray
    bmCopy.addObject("Google")
    defaults.setObject(bmCopy, forKey:"bookmarks")
 }

Upvotes: 5

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