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POcellForRowAtIndexPath: for StoryBoard and XIB Behaviour and Cell caching mechanism?
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copied!<p>I am new in iOS Development. I do not understand behaviour of tableView. <br/> To test it, I have made two Simple tableView application and I have loaded tableView with 99999 rows with standard code snippet in both cases , if user scrolls down till the end of tableView.</p> <p><br/> <strong>App 1 : TableViewWithStoryBoard cellForRowAtIndexPath: code snippet</strong></p> <pre><code>- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath]; // for StoryBoard if (cell == nil) { static int i; NSLog(@"New Cells created: %d ",++i); cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier]; } // Configure the cell... cell.textLabel.text = [self.tableData objectAtIndex:indexPath.row]; return cell; </code></pre> <p>}</p> <p><strong>Question 1:</strong> If I remove </p> <pre><code>forIndexPath:indexPath from UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath]; // for StoryBoard </code></pre> <p>then StoryBoard still functions properly in simulator? Then why it has been provided ?</p> <p><strong>Question 2:</strong> Why NSLog(@"New Cells created: %d ",++i); never gets printed even if i scroll down to 99999 rows that is end of my tableView? In what scenario NSLog will print some values ? </p> <p><br/> <br/></p> <p><strong>App 2: TableViewWithNib cellForRowAtIndexPath: code snippet</strong></p> <pre><code>- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; // for Nib File if (cell == nil) { cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier]; } // Configure the cell... cell.textLabel.text = [self.tableData objectAtIndex:indexPath.row]; return cell; </code></pre> <p>}</p> <p><strong>Question 3:</strong> If I add </p> <pre><code>forIndexPath:indexPath </code></pre> <p>in the XIB Version then my application crashes and throws an Exception? Why is it so ? <br/> <br/> Exception or Error: Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'unable to dequeue a cell with identifier Cell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard'</p>

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