Question

I have an array with several NSString element in and I also have a view, where i have a search bar in. I want to begin searching for what the user writes in the search field as a substring for each NSString element. If the NSString element contains the substring, i want to add it to a new array. I have tried to do this with code, and it works okay, but it keep adding objects to, even it have already for them, so does anybody have any ideas why? I have already set the delegate to self.

//.h
@interface class1

@property(strong, nonatomic) NSMutableArray *allExercisesNames;
@property (weak, nonatomic) IBOutlet UISearchBar *searchBar;
@property(strong, nonatomic) NSMutableArray *foo;

@end

//.m

@implementation class1

-(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
{    
for(int i = 0; i < _allExercisesNames.count;i++)
{
    if([[_allExercisesNames objectAtIndex:i] rangeOfString:searchBar.text].location != NSNotFound)
    {
        if(_foo == nil)
        {
            _foo = [[NSMutableArray alloc]initWithObjects:[_allExercisesNames objectAtIndex:i], nil];
            [self.gridView reloadData];

        }
        else 
        {
            [_foo addObject:[_allExercisesNames objectAtIndex:i]];
            [self.gridView reloadData];
        }
    }

}

if([searchBar.text isEqualToString:@""] || searchBar.text==nil)
    //![_allExercisesNames containsObject:searchBar.text
{
    _foo = nil;
    [self.gridView reloadData];
}
} 

Answer 1

You are not assigning ‘nil’ to _foo at the top of the function, so it continues adding to the old _foo array every time you type something.

Rather, you should set _foo to a new array at the top of the function instead, so it is cleared before scanning the _allExercisesNames array.

Here is a fixed, simplified version that also makes use of ‘for (x in y)’ to make it more concise.

-(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
{
    if([searchBar.text isEqualToString:@""] || searchBar.text==nil)
        _foo = nil;
    else
    {
        _foo = [NSMutableArray new];
        for(NSString *exercise in _allExercisesNames)
            if([exercise rangeOfString:searchBar.text].location != NSNotFound)
                [_foo addObject:exercise];
    }

    [self.gridView reloadData];
}