Re: isEqualToArray: returning NO for equal arrays
Re: isEqualToArray: returning NO for equal arrays
- Subject: Re: isEqualToArray: returning NO for equal arrays
- From: "Marc Wan" <email@hidden>
- Date: Fri, 3 Nov 2006 09:24:02 +0800
On 11/3/06, Rosyna <email@hidden> wrote:
I've got two equal arrays that contain an array of dictionaries
containing two objects each (an NSDate and an NSString).
If I compare them with isEqualToArray:, they're marked as not equal.
However, if I iterate the arrays and compare the dictionaries with
isEqualToDictionary: none of them are considered to be unequal. I
don't get it.... Why is isEqualToArray: returning NO (the last 0
after the output of each array)?
NSDictionary isEqualToDictionary checks to see if the two dictionaries
have similar VALUES for similar KEYS. These values are nearly always
actually in separate objects: [NSString stringWithString: @"Poisson"] and
[NSString stringWithString: @"Poisson"] have similar values, but are
different Objective-C objects.
NSArray isEqualToArray compares two arrays to see if the values are the
same by using the isEqual method. I'm not 100% sure here how deep/rich the
Foundation Framework is, but I would suspect that the problem is that the
NSDictionary isEqual method only returns TRUE/YES if they're actually the
same object (which is why they implemented the isEqualToDictionaryMethod).
Somewhere there, a method is comparing object pointers and not the
underlying values.
That'd be what I'd investigate first.
If you know they're both holding nsdictionaries, the simple fix, of course
is:
- (BOOL)isArray1: (NSArray *)arr1 equalToArray2: (NSArray *)arr2
{
int i;
for (i = 0; i < [arr1 count]; i++)
{
if (i < [arr2 count])
{
if (![[arr1 itemAtIndex: i] isEqualToDictionary: [arr2 itemAtIndex:
i]])
return NO;
}
else
return NO;
}
return YES;
}
good ruck!
marc.
Sincerely,
Rosyna Keller
Technical Support/Carbon troll/Always needs a hug
Unsanity: Unsane Tools for Insanely Great People
It's either this, or imagining Phil Schiller in a thong.
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