isEqualToString not comparing properly - nsstring

Question

I'm trying to do a string comparison on two strings stored in two different arrays. 90% of the time it works but the other 10% of the time it does not. In this case I am comparing town names.
Below is my code:
//setup of string comparison
NSString* string1 = [information from array 1];
NSString *string2 = [information from array 2];
//remove whitespace.
NSArray* string1sep = [string1 componentsSeparatedByCharactersInSet :[NSCharacterSet whitespaceCharacterSet]];
NSString* string1rw = [string1sep componentsJoinedByString:#""];
string1rw = [string1rw lowercaseString];
NSArray* string2sep = [string2 componentsSeparatedByCharactersInSet :[NSCharacterSet whitespaceCharacterSet]];
NSString* string2rw = [string2sep componentsJoinedByString:#""];
string2rw = [string2rw lowercaseString];
//compare strings
NSLog(#"%# (%u): %# (%u)", string1rw, [string1rw length], string2rw, [string2rw length]);
if([string1rw isEqualToString:string2rw]){
NSLog(#"Success");
}
my code is wrapped in a for loop that checks each element of the array. the output looks like so
-----------------------
Identifier 1
whangarei (9): whangarei (9)
whangarei (9): kaitaia (7)
whangarei (9): kerikeri (8)
whangarei (9): paruabay (8)
whangarei (9): kamo (4)
whangarei (9): tutukaka (8)
whangarei (9): auckland (8)
whangarei (9): kaiparacoast (12)
whangarei (9): paihia (6)
whangarei (9): hikurangi (9)
whangarei (9): hokianga (8)
whangarei (9): tba (3)
failure
-----------------------
Identifier 2
kaiparacoast (12): whangarei (9)
kaiparacoast (12): kaitaia (7)
kaiparacoast (12): kerikeri (8)
kaiparacoast (12): paruabay (8)
kaiparacoast (12): kamo (4)
kaiparacoast (12): tutukaka (8)
kaiparacoast (12): auckland (8)
kaiparacoast (12): kaiparacoast (12)
Success
The strings are both the same length, both spelled the same, both de-capitalized, both have white space removed. why does this work with one string but not another?
For peoples reference this is my original uncleaned code (bit harder to read)
- (BOOL) addToFilteredResults: (int) ofset{
int catCount = 0;
int citCount = 0;
NSLog(#"-----------------------");
NSLog(#"%#", [[CHARTeventsFull objectAtIndex:ofset]objectForKey:#"event"]);
for(NSString *cityCheck in eventCities){
if([[citySelected objectAtIndex:citCount] isEqual:[NSNumber numberWithBool:YES]]){
//setup of string comparison
NSArray* cityChecksep = [cityCheck componentsSeparatedByCharactersInSet :[NSCharacterSet whitespaceCharacterSet]];
NSString* cityCheckrw = [cityChecksep componentsJoinedByString:#""];
cityCheckrw = [cityCheckrw lowercaseString];
NSString *city = [[CHARTeventsFull objectAtIndex:ofset]objectForKey:#"town"];
NSArray* citysep = [city componentsSeparatedByCharactersInSet :[NSCharacterSet whitespaceCharacterSet]];
NSString* cityrw = [citysep componentsJoinedByString:#""];
cityrw = [cityrw lowercaseString];
//comparison
NSLog(#"%# (%u): %# (%u)", cityrw, [cityrw length], cityCheckrw, [cityCheckrw length]);
if([cityCheckrw isEqualToString:cityrw]){
//doing another comparison here this code can be ignored for this question
//----------------------------
for(NSString *categoryCheck in eventCatagories){
if([[catagorySelected objectAtIndex:catCount] isEqual:[NSNumber numberWithBool:YES]]){
NSArray *categoriesFromEvent = [[CHARTeventsFull objectAtIndex:ofset]objectForKey:#"categories"];
for (NSString *category in categoriesFromEvent) {
NSLog(#"%# : %#", category, categoryCheck);
if([categoryCheck isEqualToString:category]){
NSLog(#"Success");
return YES;
}
}
}
catCount++;
}
//---------------------------
}
}
citCount++;
}
NSLog(#"failure");
return NO;
}

Answer 1

You check if cityCheckrw is equal to cityrw, but you don't print "success" unless it makes it through your second check (the one you say we can ignore). It seems much more likely that the problem is in the second check or in the second for-loop than that two identical strings are not evaluating as equal. Does it still not print "success" when you move that NSLog to be right under the cityCheckrw/cityrw check?

Answer 2

I have sorted out the problem. I have abandoned using 'isEqualToString' and am now using predicates. no idea why 'isEqualToString' does not work 100% of the time but used basically the same structure with predicates and it worked perfectly. Here is a cleaned up version of what i did with predicates for those having the same problem
1 tier solution
this has
arrayOfObjects which never changes
filteredArrayOfObjects which changes when filtered
filterArray1 which has the filters stored in it
filterArray1Selected which has a BOOL indicating if the filter is active
and the code
//remove all objects from the filter array
[filteredArrayOfObjects removeAllObjects];
//set up compounder
NSMutableArray *compounder = [[NSMutableArray alloc] init];
int count = 0;
//go though the filter array and compound all the filters that are active
for(NSString *Check in FilterArray1){
if([[filterArray1Selected objectAtIndex:count] isEqual:[NSNumber numberWithBool:YES]]){
[compounder addObject:[NSPredicate predicateWithFormat:#"(filterName == %#)", Check]];
}
count++;
}
//compound the filters
NSPredicate *compounded = [NSCompoundPredicate orPredicateWithSubpredicates:compounder];
//filter the array
NSMutableArray *filteredArrayOfObjects = [[NSMutableArray alloc] initWithArray: [ArrayOfObjects filteredArrayUsingPredicate:compounded]];
have a 2 tier solution too but it gets messy