How to find the line of the crash? - ios

Question

I have some beginner trouble using xCode. Each time the app crash I find it hard to find the problem as I don't understand the log currently I seem to have a problem with a Array. I think it is a Array of which I deleted the class where it was in.
I would like to know how I should read this log :
2014-05-02 10:49:32.808 myCompany[2793:60b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSArrayM insertObject:atIndex:]: object cannot be nil'
*** First throw call stack:
(
0 CoreFoundation 0x017f21e4 __exceptionPreprocess + 180
1 libobjc.A.dylib 0x015718e5 objc_exception_throw + 44
2 CoreFoundation 0x017a4abc -[__NSArrayM insertObject:atIndex:] + 844
3 CoreFoundation 0x017a4760 -[__NSArrayM addObject:] + 64
4 UIKit 0x00794a4b PushNextClassForSettingIMP + 383
5 UIKit 0x00794838 __workaround10030904InvokeWithTarget_block_invoke + 29
6 UIKit 0x00284413 +[UIView _performCustomizableAppearanceModifications:] + 26
7 UIKit 0x00794810 workaround10030904InvokeWithTarget + 940
8 UIKit 0x0078ee71 +[_UIAppearance _applyInvocationsTo:window:matchingSelector:] + 3779
9 UIKit 0x0078f633 +[_UIAppearance _applyInvocationsTo:window:] + 55
10 UIKit 0x0029b5a3 -[UIView(Internal) _applyAppearanceInvocations] + 270
11 UIKit 0x0029c002 __88-[UIView(Internal) _performUpdatesForPossibleChangesOfIdiom:orScreen:traverseHierarchy:]_block_invoke + 65
12 UIKit 0x0029bf8f -[UIView(Internal) _performUpdatesForPossibleChangesOfIdiom:orScreen:traverseHierarchy:] + 204
13 UIKit 0x0029bebe -[UIView(Internal) _didChangeFromIdiom:onScreen:traverseHierarchy:] + 52
14 UIKit 0x003f44b7 -[UILabel(_UIAccessibilityButtonShapesSupportInternal) _didChangeFromIdiom:onScreen:traverseHierarchy:] + 73
15 UIKit 0x004ed776 -[UITabBarButtonLabel _didChangeFromIdiom:onScreen:traverseHierarchy:] + 73
16 UIKit 0x0029be82 -[UIView(Internal) _didChangeFromIdiomOnScreen:traverseHierarchy:] + 172
17 UIKit 0x0029b466 -[UIView(Internal) _didMoveFromWindow:toWindow:] + 1624
18 UIKit 0x0029b109 -[UIView(Internal) _didMoveFromWindow:toWindow:] + 763
19 UIKit 0x00334458 -[UIControl _didMoveFromWindow:toWindow:] + 65
20 UIKit 0x0029b109 -[UIView(Internal) _didMoveFromWindow:toWindow:] + 763
21 UIKit 0x004fad59 -[UITabBar(UITabBarPrivate) _didMoveFromWindow:toWindow:] + 65
22 UIKit 0x0029b109 -[UIView(Internal) _didMoveFromWindow:toWindow:] + 763
23 UIKit 0x0029296f __45-[UIView(Hierarchy) _postMovedFromSuperview:]_block_invoke + 158
24 UIKit 0x002927fb -[UIView(Hierarchy) _postMovedFromSuperview:] + 260
25 UIKit 0x0029ddd4 -[UIView(Internal) _addSubview:positioned:relativeTo:] + 1875
26 UIKit 0x00290dba -[UIView(Hierarchy) addSubview:] + 56
27 UIKit 0x00270406 -[UIWindow addRootViewControllerViewIfPossible] + 481
28 UIKit 0x002705ef -[UIWindow _setHidden:forced:] + 312
29 UIKit 0x0027086b -[UIWindow _orderFrontWithoutMakingKey] + 49
30 UIKit 0x0027b3c8 -[UIWindow makeKeyAndVisible] + 65
31 UIKit 0x0022bbc0 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 2097
32 UIKit 0x00230667 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 824
33 UIKit 0x00244f92 -[UIApplication handleEvent:withNewEvent:] + 3517
34 UIKit 0x00245555 -[UIApplication sendEvent:] + 85
35 UIKit 0x00232250 _UIApplicationHandleEvent + 683
36 GraphicsServices 0x037e7f02 _PurpleEventCallback + 776
37 GraphicsServices 0x037e7a0d PurpleEventCallback + 46
38 CoreFoundation 0x0176dca5 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53
39 CoreFoundation 0x0176d9db __CFRunLoopDoSource1 + 523
40 CoreFoundation 0x0179868c __CFRunLoopRun + 2156
41 CoreFoundation 0x017979d3 CFRunLoopRunSpecific + 467
42 CoreFoundation 0x017977eb CFRunLoopRunInMode + 123
43 UIKit 0x0022fd9c -[UIApplication _run] + 840
44 UIKit 0x00231f9b UIApplicationMain + 1225
45 myCompany 0x000043fd main + 141
46 libdyld.dylib 0x01e39701 start + 1
)
EDIT :
this caused the problem :
UIImage *tabBackground = [[UIImage imageNamed:#"image.PNG"]
resizableImageWithCapInsets:UIEdgeInsetsMake(0, 0, 0, 0)];
[[UITabBarItem appearance] setImage:tabBackground];
Still I don't understand why it can't just display the line of error like android. I found this by comment lining

Answer 1

I think you must follow up this tutorial, clearly mentioning about this
http://www.raywenderlich.com/10209/my-app-crashed-now-what-part-1
According to your log details,
You are trying to create array with nil objects.
Trying to insert nil object to array
both above will crash the app.
Enable zombies
Product->Edit Scheme->Diagnostics-> Click Enable Zombie Objects
You forgot to add nil at last index in array creation.
like this
NSArray *array = [NSArray arrayWithObjects:#"1",#"2"]; 
But it should be
NSArray *array = [NSArray arrayWithObjects:#"1",#"2",nil]; 
But If you are using NSMutableArray and add objects,then u should valid to nil condition like below.
if (myObjectToBeAddedToArray!=nil) {
[arrayMutable addObject:myObjectToBeAddedToArray];
}