Remove duplicates from NSArray case insensitively using NSSet - ios

Question

NSArray*arr = #[#"ram",#"Ram",#"vinoth",#"kiran",#"kiran"];
NSSet* uniqueName = [[NSSet alloc]initWithArray:arr];
NSLog(#"Unique Names :%#",uniqueName);
Output:
but i need the output as

Answer 1

You could first convert them all to lowercase strings.
NSArray *arr = #[#"ram",#"Ram",#"vinoth",#"kiran",#"kiran"];
NSArray *lowerCaseArr = [arr valueForKey:#"lowercaseString"];
NSSet* uniqueName = [[NSSet alloc] initWithArray:lowerCaseArr];
NSLog(#"Unique Names :%#",uniqueName);
Unique Names :{(
ram,
kiran,
vinoth
)}

Answer 2

Try this:
NSArray *arr = [NSArray arrayWithObjects:#"Ram",#"ram", nil]; //this is your array
NSMutableArray *arr1 = [[NSMutableArray alloc]init]; //make a nsmutableArray
for (int i = 0; i<[arr count]; i++) {
[arr1 addObject:[[arr objectAtIndex:i]lowercaseString]];
}
NSSet *set = [NSSet setWithArray:(NSArray*)arr1];//this set has unique values

Answer 3

This will always preserve casing form that was existing in your original container (although it's undefined which casing):
NSArray<NSString*>* input = ...
NSMutableDictionary* tmp = [[NSMutableDictionary alloc] init];
for (NSString* s in input) {
[tmp setObject:s forKey:[s lowercaseString]];
}
return [tmp allValues];

Answer 4

Create a mutable array the same size as arr. Fill it with lowercaseString versions of each element of arr. Make the set out of that.

Answer 5

#Updated
Using this you remove uppercase string from your array.
NSMutableArray *arr= [[NSMutableArray alloc]initWithObjects:#"ram",#"Ram",#"vinoth",#"kiran", nil];
NSMutableArray *arrCopy = [[NSMutableArray alloc]init];
for (int index = 0 ; index<arr.count; index++) {
NSUInteger count = [[[[arr objectAtIndex:index] componentsSeparatedByCharactersInSet:[[NSCharacterSet uppercaseLetterCharacterSet] invertedSet]] componentsJoinedByString:#""] length];
if (count == 0) {
[arrCopy addObject:[arr objectAtIndex:index]];
}
}
NSLog(#"Print Mutable Copy %#",arrCopy);

Answer 6

try this one
NSArray *copyArray = [mainArray copy];
NSInteger index = [copyArray count] - 1;
for (id object in [copyArray reverseObjectEnumerator]) {
if ([mainArray indexOfObject:object inRange:NSMakeRange(0, index)] != NSNotFound) {
[mainArray removeObjectAtIndex:index];
}
index--;
}
copyArray=nil;