How to remove duplicate values from array

Question

I have one NSMutableArray which containing duplicates value e.g.[1,2,3,1,1,6]. I want to remove duplicates value and want new array with distinct values.

Solution 1

two liner

NSMutableArray *uniqueArray = [NSMutableArray array];

[uniqueArray addObjectsFromArray:[[NSSet setWithArray:duplicateArray] allObjects]];

Solution 2

My solution:

array1=[NSMutableArray arrayWithObjects:@"1",@"2",@"2",@"3",@"3",@"3",@"2",@"5",@"6",@"6",nil];
array2=[[NSMutableArray alloc]init];
for (id obj in array1) 
{
    if (![array2 containsObject:obj]) 
    {
        [array2 addObject: obj];
    }
}
NSLog(@"new array is %@",array2);

The output is: 1,2,3,5,6..... Hope it's help you. :)

Solution 3

I've made a category on NSArray with this method in :

- (NSArray *)arrayWithUniqueObjects {
    NSMutableArray *newArray = [NSMutableArray arrayWithCapacity:[self count]];

    for (id item in self)
        if (NO == [newArray containsObject:item])
            [newArray addObject:item];

    return [NSArray arrayWithArray:newArray];
}

However, this is brute force and not very efficient, there's probably a better approach.

Comments

[Gajendra Rawat]

hi can you tell me can i count no of duplicate element in array1 like 2 is coming in thrice time.

[Cœur]

And use NSOrderedSet if you want the original order.