Question

Somewhere in - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {:

static NSString *CellIdentifier = @"TagCell";
TagCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier
                                                forIndexPath:indexPath];

vs

NSString *CellIdentifier = NSStringFromClass([TagCell class]);
TagCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier
                                                forIndexPath:indexPath];

I think the first example better for performance, but the second better for refactoring.

I always use the second way.

Big a difference in performance between these code samples?

Answer 1

There is no noticeable performance difference between the two, because rendering of cells is dominated by drawing, not obtaining a class name. Your second code snippet survives refactoring better, so you should continue using it.