CODEWITHSUNDEEP
objective-c
Abhishek Bedi
Abhishek Bedi

Reputation: 5451

Compiler Overhead: How much overhead does an IF condition in objectiveC impose?

Please refer to the code below:

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

    static NSString *CellIdentifier = @"Cell";    
    UITableViewCell *cell = (UITableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
                              reuseIdentifier:CellIdentifier];
    [cell setSelectionStyle:UITableViewCellSelectionStyleNone];
     }

 //... some other code 
 if (imageLoadingQueue == nil) {
    imageLoadingQueue = [[NSOperationQueue alloc] init];
    [imageLoadingQueue setName:@"Image Loading Queue"];
}
//... some other code 

return cell;
}

Now as we know the method - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath is called every time we scroll but refer to the conditions: if (cell == nil) & if (imageLoadingQueue == nil). This condition is checked again & again always.

So I wanted to know how much performance overhead this if condition costs ?

EDIT: How do we measure that ? Any tool ?

Upvotes: 0

Views: 212

Answers (1)

paxdiablo
paxdiablo

Reputation: 881303

The if statement itself will be negligible. It's possible that the condition used within the if statement may be significant (as in if (somethingThatTakesTenSeconds()) ...) but not so in this case, simply checking pointers against the nil value.

In any case, it hardly matters. If you need to select whether or not something happens, you have to use a selection statement, be it if, select, or a ternary operation. So how onerous it is doesn't really enter into the equation.

Upvotes: 4

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