Integers not properly returned from a property list (plist) array in Objective-C
- by Gaurav
In summary, I am having a problem where I read what I expect to be an NSNumber from an NSArray contained in a property list and instead of getting a number such as '1', I get what looks to be a memory address (i.e. '61879840'). The numbers are clearly correct in the property list. Below is my process for creating the property list and reading it back.
Creating the property list
I have created a simple Objective-C property list with arrays of integers within one root array:
<array>
<array>
<integer>1</integer>
<integer>2</integer>
</array>
<array>
<integer>1</integer>
<integer>2</integer>
<integer>5</integer>
</array>
... more arrays with integers ...
</array>
The arrays are NSArray objects and the integers are NSNumber objects. The property list has been created and serialized using the following code:
// factorArray is an NSArray that contains NSArrays of NSNumbers as described above
// serialize and compress factorArray as a property list, Factors-bin.plist
NSString *error;
NSString *rootPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES)
objectAtIndex:0];
NSString *plistPath = [rootPath stringByAppendingPathComponent:@"Factors-bin.plist"];
NSData *plistData = [NSPropertyListSerialization
dataFromPropertyList:factorArray
format:NSPropertyListBinaryFormat_v1_0
errorDescription:&error];
Inspecting the created plist, all values and types are correct.
Reading the property list
The property list is read in as Data and then converted to an NSArray:
NSString *path = [[NSBundle mainBundle] pathForResource:@"Factors" ofType:@"plist"];
NSData *plistData = [[NSData alloc] initWithContentsOfFile:path];
NSPropertyListFormat format;
NSString *error = nil;
NSArray *factorData = (NSArray *)[NSPropertyListSerialization
propertyListFromData:plistData
mutabilityOption:NSPropertyListImmutable
format:&format
errorDescription:&error];
Cycling through factorData to see what it contains is where I see the erroneous integers:
for (int i = 0; i < 10; i++) {
NSArray *factorList = (NSArray *)[factorData objectAtIndex:i];
NSLog(@"Factors of %d\n", i + 1);
for (int j = 0; j < [factorList count]; j++) {
NSLog(@" %d\n", (NSNumber *)[factorList objectAtIndex:j]);
}
}
I see all the correct number of values, but the values themselves are incorrect, i.e.:
Factors of 3
61879840 (should be 1)
61961200 (should be 3)
Factors of 4
61879840 (should be 1)
61943472 (should be 2)
61943632 (should be 4)
Factors of 5
61879840 (should be 1)
61943616 (should be 5)
