How to remove NSDictionary while iterating in NSMutableArray [duplicate] - ios

Question

This question already has answers here:
Avoiding "NSArray was mutated while being enumerated"
(11 answers)
Closed 7 years ago.
I want to remove object from array when the name is same. How to do this? Thanks in advance. Here is my code
NSString *name1;
NSString *name2;
NSArray *copyArray = [uniqueArraySort copy];
for (NSMutableDictionary *dict1 in copyArray) {
for (NSDictionary *dict2 in uniqueArraySort) {
name1 = [dict1 valueForKey:#"name"];
name2 = [dict2 valueForKey:#"name"];
if ([name1 isEqualToString:name2]) {
NSLog(#"%#",uniqueArraySort);
[uniqueArraySort removeObject:dict2];
NSLog(#"%#",uniqueArraySort);
}
}
}
And when I compile I get this error
<__NSArrayM: 0x7fea39804f40> was mutated while being enumerated.'

Answer 1

Try something like this... I assume value for key "name" might be a string.
NSSet *set = [NSSet setWithArray:[uniqueArraySort valueForKey:#"name"]];
NSMutableArray *array = [NSMutableArray new];
for (NSString* value in set.allObjects) {
NSArray *filteredArray = [uniqueArraySort filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:#"name = %#", value]];
if(filteredArray.count > 0)
[array addObject:[filteredArray firstObject]];
}
return array;
UPDATE : On second thought, I found that code above is still too much. You can do it at O(n) using hashtable.
NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] initWithCapacity:uniqueArraySort.count];
for(NSDictionary *item in uniqueArraySort)
{
NSString *name = [item objectForKey:#"name"];
if([dictionary objectForKey:name] == nil)
{
[dictionary setObject:item forKey:name];
}
}
return dictionary.allValues;

Answer 2

What you need to do is create a separate mutable array. Something like this:
NSMutableArray *itemsToDelete = [NSMutableArray array];
NSMutableArray *copyArray = [uniqueArraySort mutableCopy];
for (NSMutableDictionary *dict1 in copyArray) {
for (NSDictionary *dict2 in uniqueArraySort) {
name1 = [dict1 valueForKey:#"name"];
name2 = [dict2 valueForKey:#"name"];
if ([name1 isEqualToString:name2]) {
NSLog(#"%#",uniqueArraySort);
[itemsToDelete addObject:dict2];
NSLog(#"%#",uniqueArraySort);
}
}
}
[copyArray removeObjectsInArray:itemsToDelete];
Also, I'm not sure what you are doing with uniqueArraySort but you might need to make that an NSMutableArray if you plan on using it after.