Populating UITableView cells - iphone

Question

Ok so I have wrote some code in this function:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
NSLog(#"tableviwcell is getting called");
properties = [NSUserDefaults standardUserDefaults];
NSDictionary *events_dict = [properties objectForKey:#"events_dict"];
NSDictionary *events = [events_dict objectForKey:#"event"];
am_participants = [events objectForKey:#"amParticipants"];
pm_participants = [events objectForKey:#"pmParticipants"];
UITableViewCell *cell = nil;
cell = [tableView dequeueReusableCellWithIdentifier:#"currentCell"];
if(cell == nil){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:#"currentCell"];
}
int sizeofam = [am_participants count];
int sizeofpm = [pm_participants count];
NSMutableArray *participants =[[NSMutableArray alloc] init];
NSLog(#"size of am: %i", sizeofam);
if(sizeofam > 0 && sizeofpm > 0){
for(int i = 0; i < sizeofam; i++){
NSDictionary *ampart_dict = [am_participants objectAtIndex:i];
NSString *ampart_email = [ampart_dict objectForKey:#"email"];
NSString *ampart_email_extra = [#"am" stringByAppendingString:ampart_email];
[participants addObject:ampart_dict];
}
for(int i = 0; i < sizeofpm; i++){
NSDictionary *pmpart_dict = [pm_participants objectAtIndex:i];
NSString *pmpart_email = [pmpart_dict objectForKey:#"email"];
NSString *pmpart_email_extra = [#"pm" stringByAppendingString:pmpart_email];
[participants addObject:pmpart_dict];
NSLog(#"%#", participants);
}
int sizeofparticipants = [participants count];
for(int i = 0; i < sizeofparticipants; i++){
NSString *participanti = [[participants objectAtIndex:i] objectForKey:#"email"];
for(int j = 0; j < sizeofparticipants; j++){
NSString *participantj = [[participants objectAtIndex:j] objectForKey:#"email"];
if([participanti isEqualToString:participantj]){
NSLog(#"Participant j: %#", participantj);
[participants removeObjectAtIndex:j];
sizeofparticipants = [participants count];
}
}
}
Basically I need to merge together the two arrays am_participants and pm_participants in to one array of participants. Each object in the array is a dictionary full of various values such as name, email etc. I then have to remove any duplicate values from the list (for example if someone is in the am list and pm list. I am doing that by removing values if their email address is the same in either list.
After this I need to display the new array of participants called 'participants' in one list by populating the cells with the list of participants.
I have set the number of cells to 30.
However The cells get populated with different names randomly when scrolling down the list as thought the array positions are being moved around aswell as duplicate values appearing.
Can someone explain what I am doing wrong?
Thanks!

Answer 1

the cell assignment code is not mentioned above but i assume that you are assigning values from participants as your cell's content as explained. The problem is you are creating your array inside cellForRowAtIndexPath:. This method gets called every time a new cell is to be displayed, thus, you are recreating your participants for every row. You need to move the code you have above to viewDidLoad or viewDidAppear.