iOS TableView在每个单元格中显示相同的对象

Question

I have a weird problem, I am setting up a very basic table view to display contacts and I have the tabelviewcontroller as shown below (I tried to include all relevant portions), but for some reason when I run the app I have the same data label appear in each table cell (all seven). Could someone please see the error I can't... thanks a lot

All the following code is from tableviewcontroller.m I make my array in view did load

- (void)viewDidLoad
{
[super viewDidLoad];

// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;

// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;

self.contacts = [NSMutableArray arrayWithCapacity:10];
Contact *contact = [[Contact alloc] init];
contact.name = @"1";
[self.contacts addObject:contact];
contact.name = @"2";
[self.contacts addObject:contact];
contact.name = @"3";
[self.contacts addObject:contact];
contact.name = @"4";
[self.contacts addObject:contact];
contact.name = @"5";
[self.contacts addObject:contact];
contact.name = @"6";
[self.contacts addObject:contact];
contact.name = @"7";
[self.contacts addObject:contact];
}

I have 1 section

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 1;
}

I have the number of rows in my array

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return [self.contacts count];
}

I create my cells here

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
ContactTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"ContactCell"];
Contact *contact = [self.contacts objectAtIndex:[indexPath row]];
cell.contactNameLabel.text = contact.name;
return cell;
}

So I'm not sure why every table cell label says "7" thank you in advance

Answer 1

In viewDidLoad

- (void)viewDidLoad {

     self.contacts = [NSMutableArray arrayWithCapacity:10];
     Contact *contact = [[Contact alloc] init];
     contact.name = @"1";
     [self.contacts addObject:contact];

     //Create new instance of Contact
     contact = [[Contact alloc] init];
     contact.name = @"2";
     [self.contacts addObject:contact];

     //Add objects same in way
}

If not created new object [[Contact alloc] init] , you were changing the same object.

Answer 2

You will need to create a new instance of Contact each time you add it to your data source. Like so

self.contacts = [NSMutableArray arrayWithCapacity:10];
    for(int i=1; i<8;i++) {
        Contact *contact = [[Contact alloc] init];
        contact.name = <some value>;
        [self.contacts addObject:contact];
    }

Hope this helps.

Answer 3

It should be like this

First Contact

 Contact *contact = [[Contact alloc] init];
    contact.name = @"1";
    [self.contacts addObject:contact];

Second Contact

    contact = [[Contact alloc] init];
contact.name = @"2";
[self.contacts addObject:contact];

Answer 4

This is because you are adding same object in each index. You need initialize a new object each time before you adding it to the array. See the below example

Contact *contact1 = [[Contact alloc] init];
contact.name = @"1";
[self.contacts addObject:contact1];
Contact *contact2 = [[Contact alloc] init];
contact.name = @"2";
[self.contacts addObject:contact2];

Answer 5

You need to create new object everytime like below code.

self.contacts = [NSMutableArray arrayWithCapacity:10];
Contact *contact = [[Contact alloc] init];
contact.name = @"1";
[self.contacts addObject:contact];

contact = [[Contact alloc] init];
contact.name = @"2";
[self.contacts addObject:contact];

contact = [[Contact alloc] init];

contact.name = @"3";
[self.contacts addObject:contact];

contact = [[Contact alloc] init];

contact.name = @"4";
[self.contacts addObject:contact];

contact = [[Contact alloc] init];

contact.name = @"5";
[self.contacts addObject:contact];

contact = [[Contact alloc] init];

contact.name = @"6";
[self.contacts addObject:contact];

contact = [[Contact alloc] init];

contact.name = @"7";
[self.contacts addObject:contact];

Answer 6

You are adding the same object to the array, so basically all the 7 items in your array are just pointers to the same object (with the value 7). Try create a new contact for each number, so like

Contact *contact1 = [[Contact alloc] init];
Contact *contact2 = [[Contact alloc] init];
Contact *contact3 = [[Contact alloc] init];

ect.